Imo, this is something you really need to talk about with your dh. He has to know how much this is bothering you. What does he want you to do if he isn't home to handle her unreasonable demands?

I think legz has a good suggestion if your dh isn't going to budge on this. Ask them for favors in return. Ask her to run to the store for you because your MS is acting up ALWAYS ask for something, anything in return. make her into the bad guy when she refuses you (which she most likely will). I know I wouldn't want to ask them for anything but what else can you do in this situation?

You could also say that you're charging for caretaker services now, like legz said. Other than that, I have no clue. Good luck, Dej.