D.P.
I have a Childcare in my home and have potty trained about a dozen children, I always ask the parents for underware. I never use pull ups because they are basically diapers. I also tell them that big girls and boys go on the potty, now we have a trampoline in my back yard and only big kids are allowed on it not babies. So this is an insentive for them. So find something that big kids do, like go to friends houses, or whatever you think she may enjoy when she is finally a big kid.
Is she talking about school and riding the bus? Let her know that only big kids can do that.