I work as a babysitter and the mother is on welfare and can't afford to pay me who will help her?

I'm assuming that you babysit a couple of houses.

Assuming that the mother is on welfare and can't afford to take care of the cost of having you babysit her children, If I were in your position, I would let her know that I would be available at only specific set times, and not very frequently. I would probably take into account their financial troubles, and do them a favor by babysitting for free whenever I would watch over her child/children, but I'd make it a point not to get over involved. I feel like doing a good deed to help them out is a great thing to take on, but it's important that you set your boundaries beforehand, so that you don't end up giving them free babysitting every day :)