J.L.
Whatever you do don't resort to the pull-ups. I have had fits with my daughter on potty training. She is 5 yrs old and still not completely trained. Her preschool teacher has her wearing panties and after the first few days of wetting herself she is now getting it. She will pick it up on her own you just might have to do more laundry for a while. Basically what my daughters teacher told me is that the training pants are just bigger diapers and it allows them to go in them without dealing with it. you might try the thicker training panties and plastic liners and see if that helps.
Jennie