Oh, this is easy:
Tell Brook you're an Australian, and that both Chase and I want him to keep you safe. If you think you guys can do without Jane, then I'd suggest going with voting her out. He'll certainly keep you safe of all the newbies if you pass that information on. Also, you can offer to pass messages from him to me, which he might find necessary now that he's lost his partner.
If you stress to Brook that I want you around, he'll keep you, I'm sure of it.