Writer back to cut family member? (6)
I believe the answer is:
nephew
'family member?' is the definition.
(I know that relative can be written as nephew)
'writer back to cut' is the wordplay.
'writer' becomes 'pen' (something which writes).
'back' shows that the letters should be reversed in order.
'to cut' becomes 'hew' (hew can mean to chop or cut).
'pen' reversed gives 'nep'.
'nep'+'hew'='NEPHEW'
(Other definitions for nephew that I've seen before include "Sister's son" , "A sibling's child" , "A young male relation" , "Edward V to Richard III relation" , "Has a duty (to do something)" .)