Desist all oral activities until further notice. If she asks just tell her she has to go "wash" first.
Alright. Just kidding, its something you can't force on somebody, but I'd be willing to bet she'll warm up to it sooner or later. Most of the gals I've dated started out that way and then just got over it eventually. I think its natural for women to be somewhat self-concious about something like that at first. Good luck! Keep trying in the throes of...well...passion (not a drug is it?)