Support for offspring? (4,2)
I believe the answer is:
prop up
'support' is the definition.
(I know that prop up is a more specific form of support)
'for offspring?' is the wordplay.
'for' becomes 'pro' (as in being 'pro' or in favour of something).
'offspring?' becomes 'pup' (pup is a kind of offspring).
'pro'+'pup'='PROP UP'
(Other definitions for prop up that I've seen before include "Give financial backing" , "Underpin" , "Support" , "Keep going" .)