Night terrors are pretty freaky! I was usually able to settle ds down with cuddling, soothing talk, and back rubbing though it sometimes took a while. No way could I just ignore it! Just because they don't remember being terrified is no reason to not try to comfort them, imo.
Like all sleep disturbances (insomnia, sleep walking, etc), they tend to happen more when someone isn't getting enough sleep. Usually they happen earlier in the night, like within the first few hours of sleep. Trying to make sure ds was well rested seemed to minimize his night terrors. It's been a while since he had one, at least a year. Perhaps that's because he is solidly out of naps (he was a late napper, still took them some days at age 5 and 6.)
Good luck. I hope they stop for your dd soon!
Mom to unschooling 4everboy since 8/01