" I am just going to remain calm, she is only here until Monday. I can't control what she says or thinks or does."
YAY!!! Now that's a change in behavior! Small steps....you're doing great. You're right, you can't control your M-in-law so take the high road. That sentiment holds true for your husband too. All you can too is watch your behavior, and stay steady for your kids.
I hope you get a good nights rest, you deserve it.