Please don’t let your hero worship of JKR (or your love of Harry Potter) make you an opponent to Native people trying to voice why Ilvermorny is problematic. Please, I’m begging you, just try to keep an open mind, be respectful, and listen to what Native readers are saying. If you’ve formed your opinions on Ilvermorny based entirely on things that white people have written, you are missing a critical perspective.
Here is a curated list of Native writings on Ilvermorny. I know Harry Potter means a lot to us, and I know it sucks to recognize that JKR may have really fucked up here, but you owe it to Native readers to at least hear their words before you brush them off.