Well I know a lot of people dislike that this manga is going the magical rout, but lets just say since a lot of the world still hates Trans People, and frankly it's clear the author is using magic as a metaphor for Transgender. In fact a lot of Manga like this is doing just that, using magic to smooth out the concept of Transgender Women and Girls. Even Ranma 1/2 could be a story about a Transgender Boy having to fight to be respected as a man.
So as a Trans Woman, I love these kinds of stories, and deep in my heart I wish that the magic was real. Ie remember the Anime Happiness, they had a trans girl character Jun, and her best day episode where she was magically transitioned 100% female. Yah, that euphoria is something most Trans folks want. Sadly Magic isn't real, so we suffer with bodies we hate, and except risky medicines and expensive surgeries if we can afford them.
So yah, give me the GB virus, send me the magic spell, hit me with the GB curse. I'm willing, sadly not going to happen.
Also she is still a trans woman, note she was dressed as a girl in school, and she seems totally fine being a girl.