I just had the experience of staying with my bff and her family. She has two kids, ages 6 and 4. I have two daughters ages 14 and 12. They do not live with me now but they did when they were young. So, exactly the same age difference. I never ever said to the older one that she owed something to the younger one because the younger one was a baby. Bff did it all the time. I never ever made my kids finish their food. Bff does it all the time. Etc etc

So I get you when you talk about disagreeing with the parenting style.

Since I was only a guest for two weeks, I basically kept my mouth shut.

I do not have other suggestions.