Annual cost of living perhaps concerning people with children (8)
I believe the answer is:
parental
'concerning people with children' is the definition.
(relating to parents)
'annual cost of living perhaps' is the wordplay.
'annual' becomes 'pa' (abbreviation for 'per annum').
'cost of living perhaps' becomes 'rental' (rent is part of the cost of living).
'pa'+'rental'='PARENTAL'
(Other definitions for parental that I've seen before include "Relating to mother and father" , "of father, perhaps" , "of some older relatives" , "Of mother and/or father" , "of old man and woman" .)