Hi, it does sound like night terrors. My daughter had them and I think it started about age 1 1/2. They wake up about 3-4 hours after falling asleep and are inconsolable. It's scary, I know. All I've read says to just hold them and they will eventually stop. Research it online and learn all you can.
We learned they happen when the child is over-tired and that was true for us. Make sure she keeps on her schedule and gets her naps, along with an early bed-time. I did read something online that talks about a technique where you wake them before the time of the terrors to interrupt the sleep cycle. You do this for a week or so and they stop. (Look online for this technique).
I will say we tried it and it worked for awhile, but they came back. My best advice is to make sure she is well-rested. My daughter did grow out of it by the time she was 5 or 6 (seems like an eternity from now but night terrors don't happen every night, it seems to go in spurts). Talk with your doctor if you need to. Good luck!
PS--Someone told me night terrors happen more to those kids who are highly intelligent...I believe it! :)