1 - 2 Weeks
She may give you a flicker of her first pre-smile - a reflex that's twice as common in girls as in boys.

4 Weeks
Your baby may produce a grin as a reaction to sounds or touch, but can't yet return your smile.

5 - 6 Weeks
She may smile when receiving a special toy, but is just as likely to smile at an angry face as a happy one.

3 Months
She starts testing laughing sounds, and now probably prefers to smile at people rather than things.

4 Months
Your baby has become a social smiler, who grins in response to other people's smiles.

6 Months
She learns to use different types of smiles - her toothy smile is to encourage people to talk to her.

9 Months
She's now an expert smiler, who saves her broadest grins for her favourite people.

Ages quoted are only examples, and individual children will vary. Speak to your health visitor if you are concerned about your child's development.