Ah yes, A classic example of the old ‘[Scapegoat son/daughter/partner] yelled at me’ trick (when in actual fact your DH sounds as if he was simply calling her out on her rubbish and she just didn’t like it

). It’s an oldie but a goodie, and narcs and borderlines in particular do it almost constantly. I think they all got sent the same Playbook From Hell. eg. Rule No 17: #When someone points out that I might’ve done something inappropriate, rather than reflect and apologise, and learning from the mistake, I will instead overreact, blame and smear the other person and then ice that toxic cake by playing the victim and lying, crying, denying or justifying to anyone else in the vicinity. (Tiresome BS, isn’t it?)
The other tried and true ploy Mommie Dearest has also used here is the old ‘I’d just be better off dead [because Scapegoat Seven and her DH are so awful to me]’ trick.
(I should add here: Whenever my own mother has said this, it’s been well nigh impossible to overcome the temptation to agree with her on that one

) Again, it’s classic borderline behaviour.
Anyway, your Mum sounds majorly tiresome and like someone it’s best to stay well away from. Like half a world away if possible. I mean, do you really have to go near her at Xmas, or ever? Sounds as if there’s no meatshield on Earth big enough to cope with her. Ugh. Good luck Seven.