My source is logic.
Hasbro's issue with the game had nothing to do with the ponies themselves, but rather the use of the trademarked characters/MLP namesake.
They can't copyright ponies as a species, the flash art style, ponies created using the flash art style, and, I also believe, Fighting is Magic is also still fair game as long as they don't put the MLP part in the name.
She's just going to create custom OC ponies with no legal connection to Hasbro.
Take away the trademarked shit and there's nothing Hasbro (or trademark/copyright laws) can do about it.