My guess is that Fizzy has gone the route of Torchy and is found mostly in the back rooms of the local gin mills giving BJs for weed and beer.
I dunno; there's no reason for her to quit hanging around Skins's island though.
She's a fascinating study because she's one of those women who's "got" to "have" a man to fulfill her, to make her complete. Even if a guy's a total loser and takes more than what he gives, well.....at least he's a man.
Women like that drive me nuts.
It's true man was made to be with woman, and woman with man, and happily that's usually the way it works out. But there are naturally-occurring anomalies, exceptions, and if one's one of those, best to simply accept, adapt, and move on.