If she doesn't want to wear pull-ups and she's been successfully potty trained before, I wouldn't go backwards. Simply buy a stack of underwear, get back to a regular routine of reminding her to go every hour or two, and reward her for success (perhaps with a sticker or an M&M).

You may need to set aside an entire week or long weekend during which Mommy's or Daddy's sole job (you can take turns) is to follow her around and make sure she has success with the potty. If an accident occurs, don't make a big deal of it. Just engage her help in clean up.

Once your daughter is given attention and guidance, it shouldn't take long to get her back on track.