edit: If you think about it: The reason she bullied Yvonne is, that she is friends with someone whose father is part of the somewhat group of people that looked down on her father (and was punished for an unproven crime, but I doubt that she really cares about that). that a lot of mental gymnasics
No, because Yvonne's father is part of the group of people who would look down on Alta's father.
Unless I've missed something from early on. Yvonne Smollett is from an ancient noble family, close to the royal family itself. That's what Alta says. And the notes say Alta's father was treated like shit by the rich and powerful he tried to bribe.
I'm not saying that justifies the bullying, but it's one less level of indirection than you state.
Unrelatedly, I re-discovered:
https://dynasty-scans.com/chapters/please_bully_me_miss_villainess_ch01#6
Elsa's possession not from the game (at least that Yvonne recalls.)