I have a bunch of questions. What kind of doctor did the study? Has any doctor discussed the possibility of complex partial seizures? It is possible to have a normal eeg (most of my sons have been normal, never catching a seizure on it. He has had some that were abnormal as well.).......
What you describe sounds to me like a complex partial depending on a few things.
1. Does she remember anything about this the next day?
2. How is she when she wakes up?
3. Does she act or seem different on the mornings after she has this happen?
She can have a regular sleep study to help rule in or out parasomnias. Usually an eeg is not going to see all that a sleep study does as far as the various sleep parasomnias.
My son has epilepsy as well as periodic limb movement disorder. He had a misdiagnosis of parasomnia for 2 years.