I think it's lovely! It will co-ordinate with all the pink that she is bound to attract - so it won't seem inappropriately adult when she's little - and yet she will be able to keep it, and keep on enjoying it, as she grows older.
It's a wonderful present to the young mum too ... whatever her decisions and her reasoning she has had a tought time already and will have more tough times to come and this is a practical yet beautiful gift for someone who is definitely now 'an adult' and starting out on her 'adult life' one way or another.
Go for it!
Helen