Well, it's true it could have been a lot of different things... panic attack, seizure, diabetes low, gas, dissociative disorder, etc.

There's no way of knowing until she opens up about it or you see enough symptoms for yourself.

Was there anyone in the room with her that you could ask when/how it started? Maybe something "triggered" her? Either way, I would be concerned about her. I hope she is okay. Be kind to her and yourself.