I Can't Be Bothered - Tumblr Posts
So in my Marcy Wu streamer AU, a lot of characters are either skinny or muscular, but that's JUST BECAUSE in Amphibia, they're shown to repeatedly run for their lives and the Plantars work on a farm, they have to do a lot of work. The only ones shown to have a little meat on their bones are either rich or in a crisis because of how dangerous their world is.
Sasha is canonically very strong (see: strength temple) and she would definitely keep that up to adulthood
Anne is shown to do a lot of athletic activities (tennis, Mauy Thai, sword fighting, etc.) and I think she constantly wants to be prepared to go back to Amphibia and run for her life and fight stuff and typical Amphibia things
Marcy does not work out whatsoever and is skinny simply because they do not eat enough. When they eventually fix their eating schedule she will be chubbier, that's just not right now
No I am not fatphobic, I have reasons for their body types