according to what you ve told your daughter likely seems to have had an attack of seizure.there different kinds of seizure with varied symptomatology.since you ve not mentioned about anything lik throwing up convulsions,drowsiness
or vomitting i presume she had an attack of absence seizure
where she jus fainted and doesnt remember anything typical of an absence seizure.
EPILEX-is a generic name for the drug valproic acid
which is the treatment of choice for absence seizures.
this drug has to be continued and later on the dosage will be tapered off and then gradually over time it wont be reqd untill she has another attck or there are frequent attacks.
there is nothing to worry just continue the medication and dont miss a dose.