didn't argue with her at all about her mom. The one thing I've learned in life is that you never disagree with a woman about their mother...
OK, so you know you can't change her feelings about her mother. Her history with her mother colors their interactions, so I'm guessing they are stressful interactions sometimes?
Now, do you think her mother ever agrees with her about these feelings, or does she argue with her about them?
Just trying to show how this works generally. Even strained family relationships can heal if the dynamic shifts and one of the parties deviates from the script.
Her mother has Alzheimer's, and is in a home. So there's not going to be any resolution for my W there. But I get your point about arguing vs. validation.