Many a bridesmaid (6)
I believe the answer is:
sister
'many a bridesmaid' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sister that I've seen before include "Female sibling" , "Female relation" , "Member of family" , "'Nurse, nun or relative (6)'" , "Nurse, nun and sibling" .)