Suggest Medication For Idiopathic Epilepsy

Hi! My daughter has a strange history of convulsions (fever convulsions in her childhood with no occurrence between ages 6 and 13 - at six she had Stevens Johnson Syndrome) Around 14 years of age she started having convulsions about once a year but each time very different in aspect. I was told it was probably lack of calcium so we had a RMN (good, except a chronic synusitis) and hoped for the better. This was last summer. This year it happened in April and in May, we had a new RMN and also went to see an ORL doctor for the synuses. The encephalogram showed the epileptic irritations so we started giving her Depakine gradually, doctor's orders who diagnozed her as having idiopathic epilepsy and my daughter now takes two pills a day (1 am and one in the evening). My question would be since she is under a lot of pressure (she is 19 now): can she eat a square of dark chocolate at least once a month?