Obviously only a little girl (3)
I believe the answer is:
lil
'obviously only a' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'little girl' is the wordplay.
'little' means to remove the last letter (the word is not quite complete).
'girl' becomes 'lily' (girl's name).
'lily' with its final letter taken off is 'LIL'.
Can you help me to learn more?
(Another definition for lil that I've seen is " 'Diamond - - ', 17's Broadway hit".)