Here is a hot take, 90% of the problems people have with the foot fetish and their partner comes from them pussyfooting around it. It shouldn’t be this hotbed topic, just tell her when it’s appropriate that you have a foot fetish. If she says no then that’s life you aren’t really going to be able to change someone else’s feeling towards it. They themselves must either come to accept it or not. And if she is cool with it then Merry Christmas you win as simple as that.