The question of children? (5)
I believe the answer is:
issue
I believe this is a double definition.
'the question' is the first definition.
(thesaurus)
'children?' is the second definition.
(thesaurus)
'of' acts as a link.
(Other definitions for issue that I've seen before include "Matter for discussion" , "Problem or concern" , "Come forth or bring out" , "Sprogs" , "Emit" .)