J.F.
This may sound simplistic, but I bet if you take the pressure off yourself and her, she will do it on her own pretty quick. It sounds to me like she is perfectly capable of going and knows when, but it's a power struggle between the two of you and she is enjoying her power over you with this issue. Kids are great at being able to tell what is important to us and stressing us out and when it's something like potty training that they have a great deal of control over, they like to use that against us. lol Relax about it. Make going potty just a normal routine of the day, no extra attention to it, just routine and mundane like getting dressed. Still stay consistant of course but take the pressure and the attention off. My son was the same way and once I started acting like it was no skin off my back if he went or not... then he decided to go for his own benefit. :)