in someone's good books
US /ɪn ˈsʌm.wʌnz ɡʊd bʊks/
UK /ɪn ˈsʌm.wʌnz ɡʊd bʊks/

1.
to be in favor with someone because you have pleased them
:
•
I'm trying to get in my boss's good books by finishing this project early.
•
She's always in her teacher's good books because she's a diligent student.