I personally do not consider it an absolute requirement, but because blood sugar problems can provoke seizures in anyone, it's a good idea to check it. If she is alert, oriented, without acute neurological deficits, has a history of epilepsy, and you didn't have to correct her sugar for her to return to baseline, I would think a blood sugar problem would be unlikely.
The chance that a patient would have a seizure or other brief alteration in consciousness and then resolves to baseline without any intervention as the result of a blood sugar drop is essentially zero. A patient that seizes from hypoglycemia is not miraculously going to be asymptomatic after the seizure, the same goes for every DFO you get at a birth when the husband sees the miracle of life.
That being said I think almost every EMS protocol is going to require or recommend a blood sugar check with an alteration in consciousness, seizures included. I also don't see any real risk to checking a BGL so in a non-resource limited environment I don't really think there is a good reason not to do it. I would also consider that often we check them (as well as many other labs) in order to prepare the chart for review; whether it be legal, peer review, or whatever else.
Even though I feel her BGL wouldn’t be the issue if she came back to baseline on her own, it doesn’t hurt to just check it The ER will ask anyways. Last PT I had during internship that seized and we got there and was 15/15 GCS I did a sugar, 4 lead, 12 lead and thorough assessment just to check off every possible differential. She ended up signing AMA anyways