Story about equine female from Scotland (6)
I believe the answer is:
lassie
'female from scotland' is the definition.
(Scottish term for a girl)
'story about equine' is the wordplay.
'story' becomes 'lie' (story can mean a fabrication).
'about' is an insertion indicator.
'equine' becomes 'ass' (ass is a kind of equine).
'lie' going around 'ass' is 'LASSIE'.
(Other definitions for lassie that I've seen before include "Cinema dog who went home" , "Movie role for several dog stars" , "Girl from Scotland and dog from film" , "TV series/film dog" , "Scots girl - film dog" .)