At home, custody is consistent (2,7)
I believe the answer is:
in keeping
'consistent' is the definition.
(thesaurus)
'at home custody' is the wordplay.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'custody' becomes 'keeping' (I've seen this before).
'in'+'keeping'='IN KEEPING'
'is' is the link.
(Other definitions for in keeping that I've seen before include "Suitable" , "appropriate" .)