Weirdly, on my most recent run-through (and it's been a few months since the last one) Jessica joined the club but they didn't do the thing where they force her to break up with Corey. She went the one time, Corey spied on her, and that was that - it never came up again in Jessica's story.You'll need Jessica to be in the Witchcraft Club for her to be able to do the spell. But if you already look masculine, then you don't need it.
Maybe I missed something. I'll have to dig through and see what flags are active.