To pee or not to pee...

I am at my wit's end with potty training! Alix showed interest over a year ago, so we bought panties and a potty seat, and started working on it. Then, I let everyone talk me out of it. I had so many people tell me not to try in the midst of packing and moving, and then having the twins...etc. Mostly people told me she would just regress when the twins came so there was no point in trying. Between her, teaching full-time, directing the school musical, being young womens president, and packing to move, I didn't have much energy left. So, I gave in. Fast forward 18 months, and still so success! Truthfully I shouldn't say no success, because she does go every once in a while, but it is almost always at my suggestion (ie. picking her up and putting her on the potty). I have tried sticker charts, M&Ms, toys, tv time, computer game time, etc. I finally got tired of buying pullups, so for the last few days we have just been doing the let it run down her leg thing- I now have several pee spots on my carpet, a mound of pee laundry, and she's still not going unless I put her on. The most frustrating thing is that I do try to make it positive and fun. I let the twins scream in the playroom for ten minutes while I sat and read stories with her on the potty. She said she didn't need to go. Less than ten minutes later I had a puddle in the middle of the living room carpet. Same thing happened yesterday. AGHHHH! What am I doing wrong?!?