My main thought was more exercise, but you say she's getting plenty. I would just try to break her attention to the obsessive licking and redirect her to do another activity. Charlie sometimes licks his paws to where I think he goes from grooming to "boredom licking", but I can say "Stop licking my paws" and he stops. (I say "my" paws because if he were to hurt them, I have to pick up the bill
)