Nightmares???

Every so often my almost 1 year old will wake up randomly in the middle of the night screaming. Most of the time it’s just for a couple minutes and she puts herself back to sleep. The most recent time she was screaming/crying so bad I went in her room and rocked her for a minute. She had sat up in her crib but was basically still asleep. Some things I read said that nightmares or night terrors could happen as early as a year old and some things I read said 18 months. Anyone else’s babe do this? I feel so bad for her.