The lovin' spoonful (obviously).
Keeping Mummy sane (e.g. taking the kids out to the play park on a Saturday morning to minimise crockery breakage resulting from a tough week).
Reminding Mummy that she is not a bad parent (or at least giving her some assurance that she is in no way as laughably incompetent as Daddy).
Keeping the peace at the in-laws.
The money, the money, the money .
Any other suggestions?