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The MIL is a pain, no doubt about it, but the LW has to step back from the violent rhetoric or it might become a reality. Then, bye bye perfect(?) marriage.
One thing that might help is reading Cary's suggestions.
Then do three things:
1) Have compassion for an uneducated and profoundly stupid woman who is threatened by you.
2) Treat her like an anthropological project. That is, eye her and her behaviour from a distance. She's amusing!; she's from a long lost tribe with which you've just made contact!
3) Ask your husband to protect you from her most grievous hurts to you. Just pick a few and ask him to speak up on your behalf if they happen. You need to feel that your little family will be protected.
Remember, your husband loves her. She will grow old and sick. He will want to take care of her. She is unhappy becuase you are "better" than her
Cary was right, change yourself, get some distance, and renegotiate with your husband so you don't feel harmed.
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