A Parent's Guide to Puberty for Girls

Watching your daughter grow up is an exciting milestone, but it can also bring plenty of questions. Every girl develops differently, and it is completely normal to wonder whether the changes you’re noticing are part of healthy development.

One of the most reassuring things to know is that puberty is a journey, not a single event. Some girls start earlier than their friends, some later, and both can be perfectly normal.

Rather than comparing your daughter with others, it’s more helpful to look at whether her development is progressing steadily over time.

What is puberty?

Puberty is the process during which a child’s body develops into an adult body capable of reproduction. It is driven by hormones released from the brain, which stimulate the ovaries to produce oestrogen. These hormones bring about changes throughout the body, affecting growth, emotions, the skin, the reproductive organs and eventually the menstrual cycle.

Puberty usually takes around 2 to 5 years to complete.

When does puberty normally begin?

For most girls, true puberty begins between 8 and 13 years of age.

The average ages are:

Breast development: 10–11 years
First period (menarche): 12–13 years

However, there is a wide range of normal, and healthy girls do not all follow exactly the same timetable.

Before Puberty: Understanding Adrenarche

Before true puberty begins, many girls experience a normal stage called adrenarche.

Adrenarche is different from puberty itself. It occurs when the adrenal glands (small glands that sit above the kidneys) begin producing increasing amounts of hormones called androgens, particularly DHEA and DHEAS.

This usually happens between 6 and 8 years of age, although it can begin a little earlier or later.

These hormones do not cause breast development or periods. Instead, they are responsible for some of the earliest physical changes that parents may notice.

Signs of adrenarche include:

Body odour becoming stronger
Oily skin
Mild acne
Pubic hair beginning to appear
Underarm hair developing
Greasier hair

Many parents assume these changes mean puberty has started, but this isn’t necessarily the case.

Breast development is the first sign of true puberty. It is caused by rising oestrogen levels from the ovaries and signals that the brain and ovaries have begun working together.

A girl may therefore develop body odour or a small amount of pubic hair one or even two years before breast development begins.

The Stages of Puberty (Tanner Stages)

Doctors describe puberty using five stages known as the Tanner Stages.

These help us understand how puberty progresses.

Tanner Stage 1 – Before Puberty

Usually before age 8

There are no visible signs of true puberty.

Hormone levels remain low and the ovaries are inactive.

Tanner Stage 2 – Early Puberty

Usually ages 8–13

This marks the beginning of true puberty.

You may notice:

Small breast buds beneath one or both nipples
Tenderness around the nipples
One breast developing before the other (very common)
A growth spurt beginning
Emotional sensitivity

Pubic hair may already be present if adrenarche has occurred, but breast development is the key sign that puberty has truly begun.

Tanner Stage 3 – Mid Puberty

Usually ages 10–14

Hormone levels continue to rise.

Changes include:

Breasts becoming larger and rounder
Darker, thicker pubic hair
Underarm hair developing
Rapid increase in height
Body odour becoming stronger
Oily skin
Acne
Vaginal discharge becoming noticeable

A clear or white vaginal discharge often appears 6–18 months before the first period. This is completely normal and simply reflects healthy oestrogen levels.

Tanner Stage 4 – Late Puberty

Usually ages 11–15

Development continues.

Girls often notice:

Continued breast growth
Widening hips
More body fat around the hips and thighs
Adult body shape developing
More mature pubic hair

The first menstrual period usually occurs during this stage.

Tanner Stage 5 – Adult Development

Usually ages 14–17

Puberty is largely complete.

At this stage:

Breasts have reached adult development (although they continue to change throughout life)
Adult pattern of pubic hair
Growth in height has almost finished
Menstrual cycles gradually become more regular

Common Signs of Puberty

Every girl is different, but common changes include:

Breast development
Growth spurts
Wider hips
Body odour
Oily hair
Acne
Pubic hair
Underarm hair
Vaginal discharge
Mood changes
Increased appetite
Changes in sleep patterns

All of these are usually part of healthy development.

Emotional Changes

Puberty affects the brain as well as the body.

Your daughter may become:

More emotional
More self-conscious
Easily embarrassed
More independent
More interested in friendships
More aware of body image
More sensitive to criticism

These emotional changes are completely normal and reflect both hormonal changes and normal brain development.

Keeping conversations open, listening without judgement and reassuring your daughter that these feelings are common can make a huge difference.

Understanding Periods

The first period usually starts around 2 to 3 years after breast development begins.

During the first few years, it is normal for periods to be:

Irregular
Sometimes light
Sometimes heavy
Several weeks or months apart
Different each month

Many girls do not ovulate regularly during the first couple of years, which is why cycles are often unpredictable.

Vaginal Discharge

Many girls notice vaginal discharge before their first period.

Normal discharge is usually:

Clear
White or cream-coloured
Mild smelling
Not itchy
Not painful

This is completely normal and helps keep the vagina healthy.

Medical advice should be sought if discharge becomes green, grey, foul smelling, blood stained (before periods have started), or is associated with itching, soreness or pain.

Growth

Girls usually experience their biggest growth spurt before their first period.

After the first period, most girls grow another 5 to 8 cm (2 to 3 inches) before reaching their final adult height.

Remember: Every Girl is Different

It is perfectly normal for:

One breast to grow before the other.
Breasts to be different sizes.
Puberty to start earlier or later than friends.
Acne to vary greatly.
Periods to be irregular at first.
Mood changes to come and go.

There is an enormous range of normal.

When Should I Speak to a Doctor?

Although most girls progress through puberty without any problems, it is sensible to seek medical advice if you have concerns.

Early Puberty

Arrange an assessment if:

Breast development begins before 8 years of age.
Periods start before 10 years of age.
Puberty progresses very rapidly over a few months.

Delayed Puberty

Speak to your doctor if:

There is no breast development by age 13.
There has been no first period by age 15.
More than 3 years have passed between breast development and the first period.
Puberty appears to start but then stops progressing.

Signs of Adrenarche That May Need Assessment

Most girls with isolated body odour or a small amount of pubic hair are developing normally.

However, seek medical advice if your daughter has:

Very early or rapidly progressing pubic or underarm hair.
Significant acne at a young age.
Rapid growth in height.
Breast development occurring alongside early pubic hair before age 8.
Deepening of the voice.
Excessive facial hair.
Enlargement of the clitoris.
Any other concerns about unusually early development.

Period Concerns

Medical advice is recommended if your daughter:

Has very heavy periods: https://www.thefemalehealthdoctor.com/how-to-handle-heavy-periods/
Bleeds for more than seven days most months.
Has severe pain causing her to miss school regularly: https://www.thefemalehealthdoctor.com/endometriosis-explained-a-chronic-inflammatory-disease-not-just-bad-periods/
Continues to have very irregular periods more than 2–3 years after they began.
Stops having periods for more than 90 days after they have become established (unless pregnancy is possible, but still needs to be checked).

Other Symptoms That Should Be Checked

Speak to a healthcare professional if your daughter develops:

Severe acne.
Excessive facial or body hair.
Significant weight loss.
Poor growth.
Persistent headaches with visual changes.
Milk leaking from the breasts.
Persistent pelvic pain.
Abnormal vaginal discharge.

How Can I Support My Daughter?

Puberty can feel exciting, confusing and sometimes overwhelming.

You can help by:

Talking openly and honestly about body changes.
Preparing her for periods before they happen.
Reassuring her that everybody develops differently.
Helping her choose her first bra when she feels ready.
Encouraging good hygiene without making her feel embarrassed.
Supporting healthy sleep, nutrition and exercise.
Letting her know that no question is too silly or embarrassing.

Sometimes the most reassuring thing a parent can say is:

“Your body is doing exactly what it’s meant to do.”

Further Information and Support

If you or your daughter would like to learn more about puberty, periods or adolescent health, the following organisations provide reliable, evidence-based information.

Childline

The childline website provides excellent information on puberty, periods and children’s health: https://www.childline.org.uk/info-advice/you-your-body/puberty/

The Great Wall of Vulva

Images of what normal vulvas look like: https://www.thegreatwallofvulva.com/labias/

Brook

Brook provides trusted advice for young people and parents on puberty, periods, relationships and sexual health: https://www.brook.org.uk/

The Lowdown

The tripadviser of contraception: https://thelowdown.com/

Recommended Books & Podcasts

Check out our Amazon List for books to help you and your daughter.

This is so Awkward: https://podcasts.apple.com/gb/podcast/this-is-so-awkward/id1576221880

Raising Teens Podcast: https://www.careforthefamily.org.uk/podcasts/raisingteens/

A Final Word for Parents

Every girl experiences puberty differently.

Some girls develop earlier, some later, and most fall somewhere in between. The changes can sometimes feel confusing or overwhelming—for both children and parents—but they are a normal part of growing up.

The most valuable thing you can offer your daughter is reassurance, honest conversations, and the confidence that she can always come to you with questions.

Social media can be a wonderful place to hear other people’s experiences, but it is not always an accurate source of medical information. Every child’s development is unique, and advice found online may not apply to your daughter. If you are worried about her health or development, speak to a qualified healthcare professional who can provide personalised advice.

Most girls move through puberty without any medical problems, and there is a huge range of what is considered normal. If something doesn’t feel right, trust your instincts. A healthcare professional can assess whether your daughter’s development is progressing as expected, provide reassurance where everything is normal, or investigate further if needed.

No concern is ever too small when it comes to your child’s health.

We can see girls from age 13 in our clinic. To book an appointment, go to this page: https://www.thefemalehealthdoctor.com/book-an-appointment/