Does this mean literally as in size, or that the girl is grown-up in some way? Or can it mean both?
I'd say both. but it's big (little girl), so literally it is about a young girl big for her age. But figuratively you can say t to an adult woman.
I say this to my 4 yr old daughter a lot
But please never to your 16 year old. She'll stop eating.
How rude, I would get a slap if I say that!!!
From your 10-year-old daughter?