Rough family vacation

I don’t even know where to start with this, so I guess I’ll just start where I’m at now. I just got back from a family vacation, and while although it was much needed, it was mentally draining. My brother and his wife don’t have the best marriage. They’re both actively seeing other people, and my brother’s wife treats the kids very poorly, physically and emotionally.

She’s even went as far as yelling directly at my niece in her face when she was lass than a year old, telling her to shut up bc she wouldn’t stop crying. Crazy work. She treats them like inconveniences. Almost every time the kids would ask her something simple like taking them to the bathroom, she would literally sigh out loud and pout like a child. One time my brother was explaining to her that they are children and do not understand a lot of things, to which she responded with “fine, I just won’t talk to them at all then.” Lmfao. And then proceeded to ignore the children for the most part the remainder of the day. When someone calls her out on her behavior in a very polite manner, her behavior only gets worse. Mind you both the kids are under the age of 10. My brother is in a very demanding profession, and sometimes works 60 hour weeks and it eats him up he can’t be there as much as he wants to be. I had a pretty rough childhood, so seeing the kids actively go through this has been a very triggering and emotional thing for me to see unravel in real time. I’m working with my therapist about this, but it still sucks seeing this unravel in real time.