imho, it's rare that "Fetish friendly" really means the provider is into fetishes.
it's kind of like GFE - it's an advertising phrase that might get guys to go visit her.
but when they get there, her defn of "Fetish friendly" is probably widely different from the guy's defn.
some technical defns are here:
http://dictionary.reference.com/browse/fetishism
my suggestion: once you've been screened, ask her what kinds of fetishes she's friendly to, which she likes, and which she doesnt like.
imho, if she goes silent or gets mildly upset, it was prolly an ad phrase.
if she comes back w/ specifics, she prolly really meant it.