R.R.
Is she afraid of the potty? Make sure she sees you and daddy using the toilet, so she knows it's normal. Get her books and DVD's showing other children going on the potty. If she is going without a diaper watch her to see when she's getting ready to go and guide her to the potty then. Set specific intervals to sit on the potty, say every 15-20 minutes at first.
Also, since she's not going in the potty while she's bare that doesn't seem to be working so I would put her in cloth training pants (not panties yet) with plastic pants over them and tell her she's not to go in them, but in the potty. Show her how to pull them down when she needs to go. She's feel the wet in them and hopefully this will be an incentive to go in the potty, rather than on herself.
If she likes rewards like stickers try the book ~ "Big Girls Use the Potty" which comes with stickers, you can give her one each time she actually uses the potty ~
http://www.amazon.com/Big-Girls-Use-Potty-Publishing/dp/0...
And, a good DVD that shows children and teaches them about using the potty, wiping and washing their hands through songs is "Potty Power" ~
http://www.amazon.com/Potty-Power-Artist-Not-Provided/dp/...
Be positive and encouraging when she succeeds and she'll come around : )