A) it is nobody else's responsibility to support these people and B) It is none of anyone's business if the girlfriend does not work full time. (She actually does work, as a babysitter, but its not full time).

They are 21 so they are legal adults and I would let this go. You cannot control them.

I know a man who has been married to a woman who NEVER worked since they got married (15 years ago), even when he went through long term unemployment. I used to give her all kinds of advice, it went in one ear and out the other. I finally just figured it is none of my business anyway. What I've learned is that people who don't like working, won't work no matter what they are told. Sometimes they won't work even if they go through extreme poverty. It is what it is.

You do NOT HAVE TO GIVE THEM MONEY.