I am one of two children and my brother will not get involved. I have Power of Attorney for her financial and medical directives. She refuses to listen to her doctor, me or anybody who is trying to help her with health issues. Usually she just takes it out on me but now she is "sharing" the same unacceptable behavior with her Assisted Living caretakers as well as myself. She is mean, nasty and getting senile which is not a good combination. I call her up to check on her and she is horrible and wont answer questions I ask. She changes subject. I see the term "respite" and I am ready to walk away for a while. She has her meds, her supplies and I manage her finances and available in case of emergency but I cannot deal with this abuse anymore. Should I get a social worker involved or just deal with the Assisted Living people and express my need to back off a while? Trust me she won't care.
Your profile does not say what your mother's infirmities are -- why she needs assistance. Is this nasty, difficult behavior something new, or just more of what she's always been like?
Does she have dementia? Is she narcissistic?
The answer to your specific question, in my opinion, is tell the AL staff your plans, and take some time off! But for the broader question of how best to deal with her without losing your own sanity it would help us to have more details about your mom.
I hope you will not have to completely disassociate yourself, as your brother has, but for now definitely take the weekend off and then work out a plan with the ALC to minimize your involvement.
Several other people here have experience with a parent like yours and I'm sure you'll be getting some experienced advice!
Hang in there!