I mean...she's in the wrong here. She can't walk out on her job multiple times, yell at her manager regularly, and also take advantage of her sick pay to go to festivals, without expecting consequences. It doesn't matter if it's justified to walk out, she needs to understand that if she does, she's quitting. (Btw, I'd be shocked if she can file for severance pay, but I guess it depends on where you live and what the manager said maybe. But ahe walked out...she quit, she wants actually fired.)

Anyway, I guess my question to you is why are you dating someone significantly less mature than you are? Across the board, if you want a mature relationship, you date someone mature.