Potty Time? Warning, lots of pee talk!

Well, the B is long gone. She did surprisingly well with the whole transition, way better than I had expected anyway. I would say the first day was of course the worst. She had a bit of trouble at bedtime on the second night. But after the 3rd day she was going down with no fuss at all. She never even asks for it anymore, and she is even sleeping a little better at night. For some unknown reason, she still wakes up a few times throughout the night, but less than she was when she had her B. So with that under our belt, I decided to see what would happen with the potty. She has had her potty for a while now and will randomly ask to sit on it here or there. Since I was prego with Lexi at the time, I never pushed her but let her pick her own little time table for when she was ready. Now that Lexi is 4 months old, I figured it was time to try a little harder. It has been a little rough but we are making some progress. I am just not sure if she is really ready or not. She finally peed for the first time a few days ago, after about 3 sippy cups!!! She went three times that morning and I thought, hey this will be easy. Wrong! Since then it has become more of a battle of wills. She is willing to sit there, for very long periods of time, but she is holding that pee in as best she can. I even went out and bought her big girl panties but she has not shown much interest. She wants Shrek panties and I have not been able to find them yet. I tried the whole letting her run around naked and we have had a few accidents and she freaks, but will still not go on the potty. The crazy thing is, she treats it like a new chair. She does not want to get off it, the other day she sat on it for almost two hours! Then once I put her diapers on, she pees. I even busted out with the M&M's, not working. We'll keep at it for a bit loger and see what happens.