Keep asking family for carriage after midnight (7)
I believe the answer is:
pumpkin
'carriage after midnight' is the definition.
(as in Cinderella)
'keep asking family' is the wordplay.
'keep asking' becomes 'pump' (as in pumping someone for answers).
'family' becomes 'kin' (synonyms).
'pump'+'kin'='PUMPKIN'
'for' acts as a link.
(Other definitions for pumpkin that I've seen before include "Gourd - source of Cinderella's coach" , "It's a Halloween tradition" , "Type of squash" , "Large round fruit - coach for Cinderella?" , "Large variety of squash" .)