Family feud

So, I’m posting this to find out what other mommas think about this situation.. My older sister has 3 kids and her boys are often rowdy. She left her kids to be watched by me, my mom and one of my sisters... While they were here her 4 year old spit in her 2 year olds face. I firmly said “We do NOT spit in people’s faces!”.... On a separate occasion, the 4 year old was being loud and trying to pull his sister down the stairs by her ankles while my infant was sleeping.. as I was walking out of my bedroom he came running up the stairs and I placed my hand on his arm (to get his attention and so he did not just run right by me) and in a firm voice I said “be quiet”... I was going to address what he was doing to his sister but His mother was home at the time and I was unaware. She was coming to get him but I didn’t know. So she gets mad at me for redirecting him.. my sister was also mad the I got onto him for spitting in his brothers face... Obviously, I will not be babysitting for her anymore since she doesn’t like when they’re redirected.. but in your unbiased opinions, would you have been uncomfortable with your sister/brother/sibling redirecting your children in this way??

Idk where to post this.