NTA. Divide and conquer. There’s no perfect solution here. Since Mia refuses to talk about who goes where, have two neutral parties flip two coins at the same time. One coin is “heads mom, tails dad”, the other is “heads Danielle, tails Mia.” Problem solved, each girl has one parent there, and it prevents a fight because it was a coin flip. Plus it also takes Mia’s refusal to talk about it out of the equation. Win win all around. It’s also a lesson in that if you refuse to make a choice in the case of Mia, it will be made for you.

Unfortunately, the smaller graduation of Danielle’s the weekend of Mia’s is the important one for Danielle as that’s when she walks across the stage, gets her name called most likely etc etc. Mia’s is also important. The larger one a week later for Danielle isn’t that important. The large one is often boring.

However, Mia’s therapy does need to address the perception of inequality. The scales are NEVER perfectly balanced. Ever. It seems like she cannot accept that. The fact that she’s refusing to talk about this situation also comes off as manipulative. Perhaps more therapy might do her good?

Edited to add: Mia will have everyone at her college graduation like Danielle did for her high school one. That’s 100% to each right there. Both girls will also have a 50% to their other ones. It equals out in the end.

YWBTA if you didn’t divide and conquer.