She retired around 2012/13. As far as I'm aware there was no particular reason. (Shrug.) She just retired, and that was that.
She did do a few other fetishes, mostly stockings/lingerie and some bondage. I bought some of her sets/clips from the "Only Tease" group of sites, and plenty from "Restrained Elegance". Links below.
I wasn't actually that interested in those fetishes in themselves, but rather that Fi was barefoot in many of the shoots! The only snag, if you do go looking for non-WAM stuff, is that her active years began in the mid-2000s, so you'll find some of her early clips aren't as high a resolution as we're used to now. I'm pretty sure she never went any further than "tasteful nudity", so I wouldn't waste time looking for anything adult, just in case you were planning on it.
There is one unreleased WAM scene in the vaults, as the Kowalskis have mentioned it a few times now, although they haven't yet made it available.