Mom wants me to invite unwanted guests to the wedding

So my mom has a brother (let’s call him Uncle Bob) was previously married to my dads sister (let’s call her Aunt Jane). Uncle Bob and aunt Jane have been divorced for a long time, but prior to that, and even a while after the divorce, our whole extended family has been very close (aunts uncles cousins etc). Uncle Bob has a second wife of about 10 years now. Second wife was nice to everyone at first, but was always very uncomfortable with aunt Jane being around, even though she’s close family. Over the years, second wife has gotten worse and worse, especially the past year or 2. She constantly starts fights with my mom and other family members, has said awful things, literally said “I hope they die” about one of my aunts. Uncle Bob obviously takes his wife’s side, and we don’t see them often now. Occasionally my mom hears from him, but it always ends in a fight. Since getting engaged this year, neither Uncle Bob or new wife have said congrats to me or my fiancé (haven’t heard from them myself in over a year, period.) I will probably still invite them to the wedding out of respect for them and my moms feelings (my mom has tried to make amends with my uncle several times, she’s still trying). New wife has 2 adult children, and one of them also has a wife who I never got along with, she was always snobby. I don’t plan on inviting new wife’s kids. I haven’t even seen them or spoke to them in 2-3 years. My fiancé and I only want close family and friends at the wedding. My mom keeps saying “I have to invite them, they’re my brothers step kids”. She gets very angry when I say I don’t want to invite them. It just feels like she’s making it about her and not respecting my feelings about the situation at all. Any advice?