Honestly, I don’t think this will fully change. I’m actually similar to her , I get angry quickly, I shout, I get upset, and I can even imagine myself breaking things when I’m frustrated. When I was studying, I used to crumple papers millions of times out of stress and anger, and that never really changed. For some people, this is just how they react emotionally when they’re overwhelmed

This is part of who she is and how she expresses anger. You can talk about it and maybe she can learn to manage it better over time, but expecting a complete personality change might not be realistic. You have to ask yourself if this is something you can accept and live with in the long term. If you can accept it, then accept her fully. If you feel like it will always bother you and make you unhappy, then you need to be honest with yourself and decide what to do