R.J.
Hey, Sarah ~
Wow, that is a lot of work with the trainer potty. Have you ever considered just having her use the "grown-up potty"? It might appeal to her even more - it did to my daughter - and you won't have to clean up AGAIN, should she decide she's not quite finished.
As for the panty vs. diaper issue, here's what we did. I took my daughter to the store - just her and mommy time - and let her choose which panties she wanted. (Chances are, you and your little girl haven't done that with diapers.) Then we got home and made a HUGE deal out of the fact that "Mercy has big girl panties now, instead of diapers!" Let her watch you pack up the rest of her diapers for donation. When she has an accident, of course you don't want to be hard on her, but you'll say something like, "Uh oh! That doesn't belong in the panties! Come on, let's go use the potty." Afterwards, let her help you rinse them out in the bathtub and then put them in the laundry basket, or just put them straight in the washer. She'll see that you don't just throw them out like diapers. Just a few suggestions to get your feet wet. (Wait, maybe that wasn't the best phrase to use...sorry.)
Happy potty training! :)
~ R.