Resist awkward family member (6)
I believe the answer is:
sister
'family member' is the definition.
(I know that Sister is a type of sibling)
'resist awkward' is the wordplay.
'awkward' indicates anagramming the letters.
'resist' with letters rearranged gives 'SISTER'.
(Other definitions for sister that I've seen before include "Female sibling" , "Nun's title" , "A relative to resist" , "of the same origin" , "Relative in hospital?" .)