J.Y.
I have a special needs child and we recently discovered she was having absent seizures. Because she also has autism, we did not notice the seizures until they progressed to prolonged "staring/freezing" episodes. Our ped. took it seriously and scheduled an EEG STAT. Of course, my daughter already has many problems so that could be why. Did the 30 sec episode occur before or after you called the ped.? That is the part that concerns me the most. TAKE VIDEO of the incidents and take them with you to the ped. and if you decide to, a pediatric neurologist. Video is an excellent tool in convincing a doctor that you are not "over exaggerating"
Seizures can occur when tired, my daughter seems to have several as she is trying to fall asleep. I am not trying to freak you out, but my point is, if you feel something is wrong...do NOT hesitate to find out for sure. She is your baby and you know her best.
Here's some info: http://www.epilepsy.com/epilepsy/seizure_absence. (You can google absent seizures, look for reputable sites: ending in .edu, .org, .gov; webmd, mayo clinic are very good resources)
We take our daughter to Dr. Schnitzler our of Loyola (Ronald McDonald house - the childrens center in OakBrook Terrace, http://loyolamedicine.org/Patient_Visitor_Info/Locations_....
Good Luck and keep us posted!!!