T
By reminding her that SHE is the caretaker for you and your sibs. That all this responsibility is too much for you to take on. By telling her she needs to help out with the kids, and cooking and cleaning and whatever else that SHE is supposed to be doing. Tell her that she at the very least needs to pay ALL the bills herself, and that the kids are HER job to deal with. She's a parent, she needs to act like one and stop sitting on her lazy duff all the time.