Girl and boy's benefactor (6)
I believe the answer is:
patron
'benefactor' is the definition.
(patron is a kind of benefactor)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for patron that I've seen before include "one of the regular customers" , "Sponsor or supporter as of the arts" , "One gives financial or other support, to an artist say" , "Pot ran out for protector" , "Restaurant customer" .)