Forgot to add....
On Friday afternoon, H mentioned that his mom was on tranquilizers when he was growing up. This surprised me because she's an unusually calm person. However if she continued to take these "mommy's little helpers" even with an empty nest, that might explain her calmness in the face of chaos.
She had to put up with a LOT with her H. (BTW...both MIL and FIL were adult children of alcoholics)
There have been a few times that MIL has "been revealing" about her (likely BPD) husband.
Years ago, we visited and took her to church (FIL didn't ever go with her). After we left the church, she asked us if we saw the man in the front pew. We said yes. She then said, "that's Joe's replacement." Shocking!
Then at their 50 year anniversary party, MIL had some champagne (neither drink much), and she got a little tipsy (empty stomach and all). Her H stood up and gave a very nice speech about how wonderful his wife is. Then is was her turn. She stood up and said, "well, Joe, when I look around the room and see our 8 kids, all I can say is: 'you had good sperm." Then she sat down. The audience was stunned.
Then, at FIL's memorial service ( a very casual affair), we stood around the grave with the cremated remains box and each person said a few words. When it was MIL's turn she said, "Now I can say whatever I want, and now I have more closet space." Wow...imagine a widow saying that??? I agree that her H refused to have anyone express ANY views contrary to his, but her comments at his gravesite were crazy!
The weird thing is that her kids didn't put 2 + 2 together. They still marvel at their parents' "perfect marriage."