Fish for small girl (5)
I believe the answer is:
skate
'fish' is the definition.
(skate is a kind of fish)
'small girl' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'girl' becomes 'Kate' (girl's name).
's'+'kate'='SKATE'
'for' is the link.
(Other definitions for skate that I've seen before include "Large marine fish" , "Edible marine fish" , "A ray; slide smoothly" , "move around ice" , "Glide on ice; ray" .)