My sister's husband has not worked in summers, has been fired from jobs, they own two houses, have through the years asked for money from parents and sold the condominium they were to inherit not realizing that the money became part of mom's estate to support her. Neither of my sisters have lifted a finger to help her care or relieve me. Now they are in panic that their inheritance is dwindling away. I have saved 92 yo mom's life many times and she lives with me now, which has smashed my career and income and has left me trapped. What is my moral/financial obligation to these people? I am considering leaving for a month at a time (a risky decision since I am needed at home even with 24 hour caretakers) to add more money for mom's care should that time come.
Regarding leaving for a month, do you want one of your siblings to move into your house or do you want your Mom to move in with them for a month?
I recommend you bring her to their house so you have some privacy.
When I took a three week holiday from caring for my Mom, I simply gave the dates to my siblings and they ended up hiring a 24/7 caretaker. Your holiday is not up for negotiation - caretakers NEED a break.