Advice pleeeee!!!?

Okk so i have been friends with this girl for a long time. We got into a big fight so now we are just more like aqquantinces. Anyways she has been lightly overweight for sometime now. She tends to hang out with me nd my friends a lot. All of my other friends are skinny and pretty nd they al hate her because she is fat and because she is so loud and gross. She weighs 215 and she is 14 and like 5"3. Idk wat to do cause im really embarred to be with her and my friends are to. Idk wat to say to her beacuse like wen we are in the mall she laugs hella loud and i just try to look away cause shes so big and embarring. I know i sound rude but its just really hard cause she wont even try to loose weight. Idk wat should i tell her , or what i should do. Shes so embarring. Help!!!!