Think of the family (5)
I believe the answer is:
brood
I believe this clue is a double definition.
'think' is the first definition.
(thesaurus)
'the family' is the second definition.
(thesaurus)
'of' acts as a link.
(Other definitions for brood that I've seen before include "Clutch" , "Offspring" , "Family of young birds" , "Ponder - family" , "Ponder mournfully" .)