Whatever solution you give her for her problems, she says "no". My mom is now blind due to macular degeneration & just moved into an assisted living facility because my brother cannot be with her 24/7. I live out of town & call frequently & have made monthly trips home the past 4 months because of her health. She is extremely mean to my brother who has always been available to her for dr. appointments, grocery shopping, companionship etc. including her in his family's activities. She hates the facility; won't try to do anything for herself like she did at home; and complains to me about my brother. He is a warm, loving, caring man and it hurts me to hear her trash him. How can I make her see that she's being mean and whatever solution you give her for her problems, she says "no".
In the overall scheme of things (look around at the world), she's one VERY LUCKY lady to have two children bending over backwards to address her every need. She's in a facility set up to care for her and she's just not appreciating her blessings. Maybe start to talk to her about that a bit when she starts in. She has money, she has people to help her, she has loving children who are trying to make her life as happy as possible. To put it bluntly, she needs to get a grip. And maybe some anti-depressants to even her out as well. :) She's very lucky to have you and your brother. Too bad she doesn't appreciate you.
As well as visiting her, will you have time to throw in a few treats for yourself during your stay? A nice meal, a hair-do, a movie or something? That might help to 'leaven the lump' as my mother used to put it.
My LO hasn't been nasty to anyone at her AL, but when any issues do arise, I have found the staff generally know how to handle the matter. They have lots of experience in deflating problems, avoiding conflicts and encouraging the resident at the same time. I wonder if they might inspire your mom.
I wonder: that might be because there isn't a solution to her problems, which mainly are that she is old, frail, losing her sight and very, very fed up about it.
I sympathise with how wearing it is to have every suggestion pooh-poohed, but honestly? Stop making them. You are wasting your breath. If there really are things that could be done that would help her - I don't know, perhaps like talking books if she used to enjoy reading, that kind of thing - just go ahead and arrange them. Don't bother consulting her, just don't expect any thanks either, and especially don't spend more money than you're content to waste because whatever you introduce may be rejected out of hand. You're doing it for your mother's benefit, not her gratitude; and more in hope than expectation.
Does any of what she says get back to your brother? If not so far, you could try calling her out on it. You could give her the home truths: that she's lucky to have his support and she'd better cut out the negativity because she'd be right up a gum tree without him. Blunt, yes; but BE blunt. She needs to know. If she persists, and you're tired of hearing it, then tell her so, in so many words. In a similar situation with my BIL and his frankly slanderous mother I used literally to say "D___, I'm not listening to this, it's outrageous." And she'd stop. Of course you don't have to argue with her if you're not happy to, but you certainly don't have to listen.
So, I suppose, it's a matter of speaking to her adult to adult and insisting on the same standards of truth and fairness (not to mention good manners) that you'd expect from anyone else. But bear in mind that she could be 'talking for effect' - just mouthing off without really meaning anything; and the good part about that is, you can just let it be and do your best to help your brother shrug it off if it's bothering him.
I'm sorry that you're in this sad situation. It is disheartening, and yes ingratitude is a hurtful thing even when it's not aimed at you. Well done you for supporting your brother, and look at next week as a chance to thrash a few things out maybe? How long will you be around her for?
Some people "pick on" the very person who helps them the most. I am not sure that you can "make" her see that she is being mean. Some people live like that and want problems to complain about, but not solutions. When I realised that about my own mother I stopped trying to "fix" things. She concentrates on the negatives - for whatever reason. However you do not have to listen to it and can draw a boundary there and let her know that you will not listen to her trashing your brother.
When she says bad things about your brother, just remind her that he is a sweetheart and you both love him. Your mother is probably angry about her circumstances and blaming him for them, though they aren't his fault. This happens a good bit. I'm glad that you're there to take up for your brother. If things go well, she will be agreeing with you soon.