Ah, see I saw the post about how a cat 40 was like a monohull 55 (can't remember the exact number). So I thought maybe that was meaning that 55 footers were couple sailable in mono format. I pretty much think she wouldn't consider a monohull but want to ensure comparing equally sailable type stuff for our discussion purposes. We are going out on a 40 foot mono next weekend but with 4 people. Should be fun regardless.
I believe her major concern on monohulls is the ballast and sinking. Maybe a steel hull solves that, dunno.