Each time, she get's angry and ends up going. I finally figured out that even more than not wanting to go, she does not want to be perceived by my family as not wanting to go.
She doesn't think in her absence you will stand up for her if they start bad-mouthing her. She wants you to choose her (your family) over your FOO when it comes time to take a stand. This is very much a emotional issue. That's why agreeing with her matters so much. I would still take action with your parents to let them know about your issues with how they treat your wife. Your Dad doesn't treat everybody this way.
Something must be done to break the cycle. DB your parents.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.
