A girl accepts it as friendship (5)
I believe the answer is:
amity
'friendship' is the definition.
(I've seen this in other clues)
'a girl accepts it' is the wordplay.
'a girl' becomes 'amy' (**).
'accepts' is an insertion indicator.
'amy' enclosing 'it' is 'AMITY'.
'as' is the link.
(Other definitions for amity that I've seen before include "warmth" , "Friendliness" , "Friendship - goodwill" , "understanding" , "Cordiality" .)