I am under the impression that everyone is allowed one seizure in their life without concern. I bet it was scary for you. My daughter had her first seizure two years ago at the age of 14.
I have learned there really isn't a "typical" seizure. It certainly sounds like your GF had a seizure. If she doesn't have another, I would just use it as a warning signal that something is amiss in her system. Her brain was overloaded for some reason. We work out a lot of our stress while we sleep. I would forget the label and find out what is lowering her threshold.
Sleep studies may or may not answer your questions. My daughter's EEGs have not been conclusive as to whether or not there is seizure activity, and I have come to learn (of course not from traditional doctors) that there are areas of the brain (frontal lobe) that are difficult to record seizure activity. Also if there is not a seizure during the EEG it will not show abnormal brain function.
My suggestion would be to stay away from the labels. They don't mean a whole lot and can get you on a nasty roll with medicines that will cause far more trouble than she is having right now.
My daughter tried four, and I believe they caused more seizures than she would have had without them. Now we are doing a combination of nutritional changes, vitamins and minerals that are targeted to her needs, and neurofeedback.
Her seizures have been reduced from six a month to .... none, at least this month.