Rant ahead. My father got laid off some time ago, and just lost his unemployment benefits due to a loophole in they system saying they don't have to pay him anymore. He's not really capable of finding employment in another field: pushing 60 years old with a disability that he also gets no benefits for thanks to another loophole... Illinois sucks. Mom works, but has her own disabilities that are starting to get in the way of such things. We have broached the possibility of my parents moving in with me. The issue is my mother. She rather mentally abusive to her children as well as to my Dad. I've been married and living out of state for a few years now, and finally getting over the games she used to play. She still has the habit of manipulation and mind-screwing. I do NOT want to live under the same roof as my mother. Seriously. And my husband is nauseous at the thought too. But we both know that we can't let them be homeless, and we can't send them money. You CANNOT give my mother money, and if you give Dad money she'll take it. Mom controlling finances is what got them to this age with NO savings and two bankruptcies. The last time I sent them money for bills, Mom bought a new computer behind Dad's back and bragged to me about it. The bills still didn't get paid that month. I know Dad doesn't want to do it, but we may not have much of a choice here before long. My sisters either won't talk to either of them or won't talk to Dad, thanks to Mom's machinations. Poor Dad. I'm dreading the possibility of sharing a house with my mother again. If this happens, it's going to royally suck. Maybe they'll move in with Dad's sister. SHE won't take Mom's crap for long, and SHE's got a Ph.D. in psychiatry to return fire with... /rant
Long story short, become mother to your mother. The only reason that she behaves the way she does is because she thinks that she is doing the right thing, that nobody is going to stop her and everyone is better off for what she does. Give her a three strike system with groundrules, much as you would give a child. She needs to realise who has the control (you, silly) and it sounds like she needs a lesson in basic human respect, this is your chance to teach her. It might be hard and upsetting, you may get angrier than you have ever got in your life and feel that you're hurting her but you will be glad you did when you succeed and you will have opened the door for love to walk right in. Also, I would recommend using a certain phrase to stop her in her tracks, something like "Before you continue, mum, I would like you to THINK about what you're doing." Or "Mum, you are causing us pain, is that what you want to do?" Anything that will make her think about her own actions. It also sounds like you must get out of your comfort zone and become mediator in your family, you all need to communicate and support each other. Is your family really happy spending their short time on earth hating each other?
You do not invite abusive people to live in your home with those you love. There shouldn't even be a question of that part. Offer your father a home, but make it clear it doesn't include her. What do you do when your husband (who is already disgusted by the idea) decides that that just because you choose to let your mother into your home that doesn't mean he has to stay and put up with it. He can say whatever he wants know... he loves you, he will likely support you in your decision... What happens in 6 months? or a year down the road? Is he going to sit back and accept your mother acting as she does towards you? him? your father even?
alternatively, you might find activities that bring your family more closer together. If your mom's pulling trips on people, you could stipulate that she has to observe the ritesof some obscure religion to even things out, tell her you've become a strict observer of mahayana buddhism and that she has to bow her head and wear a toga. Or ust take them to a unitarian universalist church? Write a movie script and make them play the parts you create?