Some seizures can cause damage to the brain, hyperthermia (which can effect all organs of the body), can cause additional trauma, can cause cardiovascular abnormalities (abnormal heart function). If the
seizure is due to an insulinoma, for example, the hypoglycemia
that the insulinoma causes can be life threatening, if untreated.
Since your dog did not lost consciousness or seize, her epilepsy may not cause her any problems.