How aweful for both of you. Definately get her to the vet as soon as possible. Have them run blood test to check for anything. Sometimes it can be a diabetic thing, epilepsy, toxins or even ear mites.
I have a female cat that has seizures and has ever since birth. We adopted her out of the back yard and within 24 hours had her at the vets for a week. They originally thought it was toxins from a pesticide. They explained that momma could walk through a yard recently treated for fleas/ticks and then pass the chemicals to their babies by nursing. Also she had ear mites pretty bad, that was the next theory, they can burrow into their little brains. She now has to take phenobarbitol and diazapam 2 times a day. She would have multiple seizures in a day...now it seems like she'll have 1 a day for about 4 days straight out of the month.
With your baby having them as infrequently as she does it is more likely related to diabetes, epilepsy or hypoglocemia. The vet should be able to run some routine tests for this and she may just need to be on a special diet to help prevent levels from getting too low. If they can't find anything through blood test you may consider a catscan done on her brain. THis is rather costly and may or may not find anything. It is a personal decision, if you decide to try it check with College Vet Schools as well as vet specialists. The equipment is not readily available at every vet office, colleges will usually be alittle cheaper than vet specialists too.
Good luck and keep us all posted!