Is OTHER wrong in the post ? POST : AITA 

I'm getting married in October, and I'm trying to keep the guest list to people who are good friends and family (we're anticipating about 100-130 guests). My wedding is in London where we live (most of my side are from Florida/the States), but my fiance is from London. My dad's side of the family is considerably larger than my mom's (parents are divorced FYI, but pretty civil), and I have always been much closer to them, but I have decided to only invite my aunts and uncles and first cousins from both sides. I have invited my uncle and his family from my mother's side because I grew up having a relationship with them and always see them when I visit. My mom has one other brother who is estranged and no one speaks to (I met him one time when I was a toddler), which is fine as she is not asking him to be invited, nor would she want him there.

However, she keeps demanding that I invite my great aunt and three of her cousins. I barely have a relationship with them. I see them once maybe every ten years, and we don't speak otherwise. I don't even know the names of some of their kids who are around my age. We're not close and never have been. I don't dislike them or anything (I don't particularly care for her aunt and one of the cousins because I find them a bit rude and weird, and one of them talked shit about me to my mom at my gran's funeral). But it's now become a huge argument between us. She's brought it up 5 times after I've repeatedly said no, and we just had a big fight about it. She thinks they might not even come, so I should just send them an invitation, but I know they have money and most are semi-retired, so I think they might. I've told her that we're only inviting my aunts, uncles, and first cousins, and I'm not inviting any of my dad's cousins or his aunts. Her argument is "they're family and would do anything for me". I told my mom that she was starting to make my wedding about her, and she implied that because I'm her daughter, it is a little about her.

I wouldn't expect to be invited to any of her cousin's kid's major life events, and I haven't been. And when I went to California, her cousin didn't offer to let me stay at her place when she had let my mom and other sisters, which is fine, I don't really mind, but to me, that takes away from the argument of "they would do anything for me". Also, one of the cousins had said my older sister could stay with her in NYC and then rescinded her offer a few weeks before she was scheduled to fly there.

Bottom line is, I'm not, nor have I ever been close with this part of my mom's family and wouldn't really want them there, but it's starting to cause problems between my mom and me. And now I'm not sure if I should just send them an invite to ease the tension between us.

AITA for not inviting them?

Side note: we have a limited budget (my dad and my fiance's parents are splitting the cost)