I, Cassiopeia Prewett Preston-Lively, Welcome You to Hell

Hogwarts is not usually hell. But after my Death Eater parents died, Gideon and Fabian Prewett became my guardians, despite being still in school. And then I started getting noticed, (which, for the first time, I could do nothing about.) Now, trapped within Hogwarts, I'm wondering which is worse: the personal interest of Voldemort or the romantic interest of Sirius Black? SB/OC