Beautifully done, Mystery Author! I loved the first- person narrative voice, which is hard to do in-character, and which you made delightfully, believably Minerva from the start. I loved too, the little touches which made deft work of reminding us of the differences between the magical world and this one.
The backstory you create for the intersections between Minerva and Myrtle and Minerva and Amelia feel very real. As other commenters have said, your passionate Amelia would make anyone fall for her, and Minerva's confusion and inaction are all too plausible. How lovely that she recognizes a second chance and doesn't let it slip away!