Family supporting relative briefly as singer (6)
I believe the answer is:
siskin
'singer' is the definition.
(siskin is a kind of birdanimal)
'family supporting relative briefly' is the wordplay.
'family' becomes 'kin' ('kin' can be a synonym of 'family').
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'relative briefly' becomes 'sis' (short for 'sister').
'kin' after 'sis' is 'SISKIN'.
'as' acts as a link.
(Other definitions for siskin that I've seen before include "Type of bird" , "Breed of finch" , "Finch akin to canary" , "Singer" , "Winger" .)