Ketogenic diet

Has any ones child started the Ketogenic diet in the last couple of months? If so how long did it take for your child to stop having seizures? My daughter has been on the diet for 7 days and is still having seizures she has had 2. I want to know if this is normal she has tonic clonic seizures and is on felbatol and zonegran am,noon and bedtime.The doctors don't want to take her off any meds until she has gone seizure free for awhile because she has been prone to long seizures in the past her longest one was 6 hours and she was in icu for three days on a resporator with that one.