My 2 1/2 year old refuses to use the potty. She done so well at one point and then now she won't use it at all. She knows what pee and poop are, what the potty is, and what it's used for. She get's excited when she pees in the potty, (which now, isn't very often) and when she follows me to the potty, she will scream Yay, good girl momm! When I pee. What do I do? She is showing all the signs for being ready, but refuses.