I disagree sort of with what Spirit said, so now you get varied suggestions :)
If she comes at you/bites you/ pop her one. Just a quick smack within a few seconds after she does it. It has to be immediate though (within 3 seconds) or she's not going to make the connection between biting and your punishment. If you can get her on a lead line (Once you catch her from the field) I would make her circle. Like spirit said, get her moving and thinking.
So she bites, you "bite" back, and then move her forward or backward away from you.
That's how I have had the best luck.