D.G.
Looks like you have received some great advice especially from those who were strong willed themselves. I am a kindergarten teacher and positive rewards for good behavior have always worked best for me in dealing with all children. With the strong willed ones it has been helpful to recognize their gifts and allow them to make choices and lead at small tasks whenever possible.
For recognizing positive behavior I have painted differenty color sections on a yardstick and given the child(ren)a clothespin to clip on and move up a section each time they do something positive. When they reach the top, they get a prize. Stickers on a chart starting with a few spaces to fill up at first and then adding more spaces works well. So does filling a jar with marbles, ping pong or golf balls. Prizes for reaching the top of the yardstick, completing a sticker chart, filling a jar, etc. should be something the child really likes.
I do not take away something earned like a marble for bad behavior because that brings the discipline back to the negative emphasis. If you need to enforce a consequence for negative behavior, I would keep it unrelated to the positive rewards. Someday you will be glad you have a strong willed child because, she will more likely be motivated and successful in life.