I will be honest, I really wish how Face in the Crowd and Cloak of the Night were differentiated better from a game mechanics standpoint. With Face in the Crowd, Rachel should fade into the background. But does that help if someone is specifically worried about or looking for her? Like Victor isn't trying to find her, but I imagine she would stand out more than usual in the crowd and he would probably be a little bit more vigilant about her presence. So how well does Face in the Crowd keep one hidden in this situation?

I think Face in the Crowd shouldn't help in such a situation, but I don't think the argument is obviously stronger for that interpretation. That said, Rachel passed her Stealth roll, so we can just assume she stays hidden.

That said again, what Face in the Crowd does do, is hide Rachel's Predatory Aura from other vampires, so Victor can't use that "sense" to find her.