really interesting, it would mean that she personally pursued and persevered when it came to treating her body, though outside of her immediate family I doubt people would know and only see her as a frail princess. I do hope they flesh her out to be like that. the appearance of a butterfly but the calm perseverance of a practitioner
with how frail her original body was, if the villainess doesn't maintain it she might actually die. or drop out of the running because she is too ill. can't wait for protagonist to meet her original family (and explore the villainess family to, hateful but pitiful I wonder how shetty the villainesses parents are).
I don't know how our protagonist will get out of the execution but I do know that she might "redeem herself" when the villainess becomes so ill that the protagonist will have to take care of her because she knows her own body the best. and they might become besties, or she might be tried for using sorcery to do such a thing. either that or the author will gloss over it all and keep it a secret, but a secret so that the two of them will survive respectively.
understand the consequences of taking over a frail but respected body, and the consequences of a ruined name