I think your uncle married her mother. Both women had the same personality, and sure, they hated each other.
I learned from my experiences and made it clear to my children what my taste is, and they know. If you can't afford something tasteful for me, then smile and visit!
Who cares about material things from others if you can afford them?
Why can't mothers live with their daughters and son-in-law and leave their daughter-in-law alone? Yep, mother and daughter can work better than a co-wife, lol!
My mother never sleeps in her sons' home, and I hope that helps the three women live in peace.