To not send present to MIL anymore?

Honestly, I wouldn't care about totally alienating her. It could happen anyway if she turns on you like she has turned on her own very helpful daughter.

You need to stop enabling her poor treatment of her DD and tell her that if she doesn't stop, you won't be making up for the loss of your SIL's help and support.

She's not going to cut you off. She needs you now that she's cut her daughter off.

...and just kept repeating "you're on her side"

I hope he kept repeating "yes, I am. She didn't steal from you. She travelled long distances to help you and you need to apologise" (or words to that effect).

I don’t see what the fight between the two has to do with you sending a card or present

So she made an eight hour return journey to do those things for her mum?

But seriously, it seems that you and your DH are being pretty weak here. "Trying to get good words in for her.." is pretty pathetic. Why aren't you losing your temper with your MIL and making it clear that her behaviour is unacceptable to you?

My mum was always difficult. I grew up scared of her right into my fifties. But when she did to my brother pretty much what your mum did to your SIL, I found the courage to totally lose it with her.

That is what your DH needs to be doing, frankly. Anything else is half-hearted. What you've done so far has had no effect whatsoever, and in the meantime, your sister is being destroyed by this false accusation and the complete withdrawal of love from her mother. Why isn't your DH incandescent with anger and properly sticking up for his sister?

Meanwhile you think that whether or not you send a card or a gift at Christmas is the issue.

How absolutely devastating for SIL. She's paid her mum's bills, she lives nearby, she's cared for her and managed areas of her life for her. But she's been accused of theft and completely rejected by her own mother for a while year.

It's your DH going to step up for her? Has he been any emotional support for her?

I'm the sibling in your DH's place (geographically advantage and not having to manage my mum's day to day needs) in a similar scenario, and I can't imagine not having fought my brother's corner.

My dad’s like this. He’s an independent 95 yr old but is forgetful. He accused me of stealing a tin of peaches and a grandchild of nicking a chess set…. both fallacious. He will dwell on his beliefs and lose sleep. I do my best to calm him by reassuring him he is mistaken and it’s ok to be forgetful. Said peaches and chess set were where (he forgot) he left them.

Similar thing happened with my late DM, accusing a NDN.
Early sign of dementia, although we had no idea at the time.

It was confirmed when she then accused the "thief" of stealing her dustbin lid, and also seducing my 82 year-old DF !

I guess she must be fairly old if she broke her hip.

Um, depends how she did it. My friend broke her hip falling off her horse, at forty five....

Absolutely this.

I'm with you on the dementia thing FWIW. I have experience of this.

I was thinking this too. A neighbour started accusing her nephew of stealing her prescription medicines and that was the beginning of her dementia.

I am afraid it is a recognised sign of dementia. Distrust and accusations.

That, or your SIL did take more than she should have and MIL whilst old, is not wrong.
Or somewhere in between. MIL forgot how much was actually there, has not properly totted up how much has been spent etc.

But don't dismiss MIL as being completely demented. Although it is a sign. So be mindful of that.

If I had been SIL I would have wanted someone with me to check the money/ count it out etc. Precisely to avoid this sort of stuff.

That’s awful! I take it that the sister isn’t likely to have stolen anything? I assume not as you’d have said. Is it loads of money? Do you think MIL has the start of dementia ? I think your DH has to take the lead and reason with his mum that of course her daughter didn’t steal money and to give over

I feel your pain op. I ended up giving my mum 16p, yes you read that correctly, because she worked out the difference in what I owed her, and kept asking me for it. This was after I had spent weeks driving to the hospital and paying to park every single day. The wear and tear on my car plus the cost of petrol and parking I sucked up. Plus the items I brought to hospital for her.
She then tells me to have all her money!
I don’t know what the answer is other than to check in regularly with SIL and make sure she is ok. Plus obviously close down mil whenever she tries to bad mouth your SIL.

Seconded, this sounds like dementia, or its foothills. That'd be a pretty typical outburst, voicing mistrust of those around her.
DH needs to get stuck in, and make sure his mother is managing.

I know this isn't really your business IP but I would be trying to pour oil on troubled waters by kindly reinforcing that this is unlikely with your MIL

No, sorry. Fuck the "kindly". He's tried that. After a year of allowing his sister to be treated so poorly, he needs to act firmly.

Id just send a christmas card and nothing else.

Dementia or not, your SIL needs to stay away, because it sounds as though her mother would be likely to continue accusing her of stuff whenever she visited the house.

But yes, your DH needs to make it clear that he is absolutely on his sister's side. I recognise that six hours is a long way away, but he cannot allow himself to be golden boy and his sister the villain, when this has gone on for a year.

The nearby sibling not only has all the pressure of caring, but also is vulnerable to this kind of accusation. Meanwhile, your husband (like me) had the benefit of being out of range of both the responsibility and the vulnerability, and is sitting pretty. I felt that the very least I could do was 100% support my brother and make it clear that I wasn't having mum making these accusations.

So forget the card and present. They're a minor issue. He needs to get up there again or get on the phone and spell it out to his mother. He and his sister need to be united.

SIL definitely shouldn't 'give back' what she didn't take. This would sent an entirely wrong message to MIL. Your SIL sounds lovely and it's sounds unlikely that a caring daughter, putting herself out to help her mother and with plenty of money of her own would do this. I know this isn't really your business IP but I would be trying to pour oil on troubled waters by kindly reinforcing that this is unlikely with your MIL rather than not sending her a present. If your kind SIL draws back from supporting HR mother, which could happen, it will cause all sorts of problems for you and your husband with probable expectations you can't meet living so far away. If you don't send a present MIL will likely feel more isolated and firm up her position..Not great whether or not dementia ends up being the cause. 🌺

@SoftandQuiet I think the biggest question before it is put down to cognitive decline is whether this is completely unlike your MIL. Or if she has always been like this in one way or another.

The problem is MIL believes it and presumably cannot countenance any "truth" other than sil stole it.
Anecdotally financial obsession to this point by a family member was the start of a vascular dementia diagnosis... so I'd be wary of being too harsh

I'd send a card and some £20 flowers....