Hmmm, that's hard to put into words. His speech was delayed. He'd "ignore" us often when he was playing. He wasn't ignoring us, he was just unable to process what we were telling him.
I felt (and was often rebuffed by the so-called experts) that he didn't understand us when we'd talk to him. Not all the time though. He'd point at body parts when asked that kind of thing but other times, he was just in his own world. I was told he had selective hearing by the neurologist. The same neurologist told me that seizures don't cause brain damage (which I'm now being told they do and that is probably what caused his delays).

Anyway, if you have access to any resources, I'd go on the assumption she has a processing issue and ask your resources for any tips on things you can do with her to improve her ability to process.
We are very blessed. We work with a behavioral specialist who recognized our son's behavior as CAPD and not ADHD (though it could be both). We just received the diagnosis of CAPD and he's only 5. The doctor said she really can't make it official yet but she was positive that he has it. She did the testing in little bits.