D.R.
Hey J.,
I am not at the potty training point yet, but from what I have read, it isn't that uncommon for kids to have mixed feelings (including fear) of using the potty. If she goes when you put her on it, then I would just suggest taking her to the potty once an hour. Make it a regular thing, just like a game. When it becomes routine, I imagine some of that fear will subside.
Just some thoughts...thanks!