Girl and donkey featured in story (6)
I believe the answer is:
lassie
'girl' is the definition.
(lassie is a kind of girl)
'donkey featured in story' is the wordplay.
'donkey' becomes 'ass' (I've seen this before).
'featured in' is an insertion indicator.
'story' becomes 'lie' (I've seen this before).
'ass' inserted into 'lie' is 'LASSIE'.
'and' is the link.
(Other definitions for lassie that I've seen before include "TV series collie dog" , "Film and TV dog" , "dog in pictures" , "Young Scottish female" , "Scots girl - film dog" .)