I haven't done PRT with DD, but I have heard good things from others who have. It's a type of ABA. PRT can be done by anyone in the child's life from a parent to an educator. On one of the autism boards I'm on, another mom said this about PRT
"PRT doesn't have a reward mentality. You work with whatever motivates the
child. PRT is all about getting inside that motivation to get the child to initiate interactions on their own.
It all started with Robert Koegel trying to isolate what was different about
the kids with autism who made the most progress. He determined that
learning to initiate with language was pivotal. So that's the "pivotal" in
Pivotal Response Treatment.
The most important thing I learned: stop doing things for him. I became a
bump on a log, or at best, I was like dragging an anchor. It was frustrating
at first for my son, but he quickly learned that I had suffered a regression
and needed his prompting for nearly everything.