Would love help seeing a circumstance as neutral

I recently went back to my hometown and visited my family. My mom and sister feed my niece and nephew horribly. They pretty much eating nothing but junk food. I can see that my niece has been gaining weight and she’s only seven. I think this brings up a lot for me because that’s how I was as a kid and my parents bed me all processed and junk food, and I now have a health condition caused by it. So I did a model that looks like this:
C: my mom got Cora a bag of starbursts, cheese its, and pizza bites.
T: They feed Cora crap
F: Angry
A: do everything I can to not say anything, tell myself this is not mine to do, spin out, get quiet, have an angry fit in my head, try to hide my anger, blame mom and sister, feel bad for neice
R: I am disconnected from them and myself

The problem here is that I dont see the C ad neutral and Im wondering how to. Maybe you can give me some ideas, because I would really like to stop being so angry and I see that Im just fighting with reality here.