Family member in Barts is terrific (6)
I believe the answer is:
sister
'family member' is the definition.
(I know that sister is a type of female sibling)
'in barts is terrific' is the wordplay.
'in' says the answer is hidden in the clue.
'SISTER' is hidden within 'barts is terrific'.
(Other definitions for sister that I've seen before include "Senior nurse; relative" , "Female sibling" , "twin?" , "Resits (anag.)" , "Close relation" .)