Hi,
Ok, I will say right up front that my daughter is very stubborn at times, but not all the time, so I don't know if this will work or not. Just stop trying. Take the potty away, take the books away, take all the potty related stuff away, and put her back in regular diapers. Make sure you put the stuff away when she's paying attention, so she sees you do it. If and when she asks what happened and where the potty went, get to her eye level and explain that you though she was ready to be a big girl and go potty like the big girls do in a potty, but that you must have been wrong. If there is anything that she is allowed to do because she's a big girl, consider taking those away because she's not a big girl. I don't like the idea of "punishing by withholding", especially for potty training, but it worked during a difficult peroid with my daughter. Another thing that worked was finding something that she was really passionate about (the little mermaid) and finding some sort of ongoing reward/goal. With Makaya, because she is so obsessed with Ariel, we came up with the on going goal that if she wanted to have a mermaid tail like Ariel, then she had to go in the potty every time like a big girl, because only big girls can have mermaid tails. This one is easy to keep going because when she askes if it's growing, I just feel her tail bone, and say "Yes! I can feel it! Do you want to feel it?" Then I help her find her "tail", and she gets so excited. It has really helped a lot since we started that reward/goal. If you need any help coming up with a reward/goal, or if you just want to talk, send me an e-mail, and we can talk that way, or I can give you a call if that's easier. ____@____.com
Good Luck!
S.