They do get nightmares too.. or go into light sleep (from deep sleep) and start to get scared. You holding her limbs for a while is comforting for her, so it’s good that she manages to go back to sleep without you picking her up:)
I think she is startled in her sleep. Can try to use swaddle and transit out of it gradually - with one arm out first then gradually both hands and lastly legs
All the best! My lo can sleep longer with swaddle as it mimics the womb
Maybe can pat her back to slp
Whai Kit Tham