it does sound like an absence seizure to me but it could be something else. i recommend taking her to a doctor. they can perform a test to determine if she has seizures.
my daughter 'zones out' for 5-20 seconds often her eyes zone or sometimes roll and she has no clue what happened during. this time. she's normally not confused but does normally say 'now what? ' or it will take her a second to recall what happened. i think this is epilepsy (the absence kind). is there anything i can do to help or reduce the occurance. she's 7 and it happens about 5 or more days a week. some times once a day sometimes multiple times over a few hours.