I haven't read this whole thread so I may be repeating what someone else said. But really children typically know when they are ready to be trained. I found it worked to just lay low and let him decide. DS was "late" training, but the day he woke up and said he wanted to wear his big boy underwear, he never had an accident. I took a very non-chalant approach and left it up to him to decide. It could be that because you want her to train, she can sense your desperation and is actually enjoying making it hard for you.

I once heard a pediatrician say that a child naturally trains around 3 years; if you work hard at it, though, you can get them trained by 36 months LOL.