Family in street, penniless (5)
I believe the answer is:
skint
'penniless' is the definition.
(I've seen this before)
'family in street' is the wordplay.
'family' becomes 'kin' ('kin' can be a synonym of 'family').
'in' indicates putting letters inside.
'street' becomes 'st'.
'kin' put into 'st' is 'SKINT'.
(Other definitions for skint that I've seen before include "Impoverished" , "bust" , "Stony broke" , "On one's uppers" , "Broke (slang)" .)