Is my brother’s girlfriend, who is 23, feeling jealous of me, a 21-year-old female?

I’d like to share a bit about my upbringing. My brother and I were homeschooled in a town often associated with incest, but that's not us at all. There's been absolutely no incest; we simply share a close bond as siblings given our unique circumstances. A couple of years ago, my brother started dating a girl who has seemed, at least subconsciously, annoyed by my presence. Even now as adults, we live together, which has become more complicated since she moved in last year. Honestly, I’d prefer not to live with either of them—she can be quite emotionally abusive, and I enjoy my own space. Unfortunately, due to financial reasons, we’re in this situation. I don’t want to delve into the specifics of how she treats both of us, but I’m looking for advice on how to help her overcome the jealousy she’s expressed towards me as the "closest woman in his life." To clarify, I’m not interested in men or my brother at all, and I thought she understood that. Should I just have a direct conversation with her?