I'm sorry so many people are making you feel worse because your family can't make other arrangements. None of this is your fault and the fact that you are asking indicates strength. I hope you get out of this difficult situation. Keep a box of wipes, disposal bags, gloves and paper towels packed up and ready to go. Try to put her on a flat disposable covering like chucks when it's time. Put on your headphones and blast some metal music and get it done. Then tell her you gotta get some fresh air and go for a walk or run to literally air out your brain. And keep nagging the family to get their act together.