Real Dictionary

girlish
If you describe a woman as girlish, you mean she behaves, looks, or sounds like a young girl, for example because she is shy, excited, or lively.

girlish in American English
of, like, or suitable to a girl or girlhood
adjective: of, like, or befitting a girl or girlhood

girlish in British English
adjective: of or like a girl in looks, behaviour, innocence, etc