Your child is likely having what are called sleep or night terrors.
These happen during deep sleep, which means that even if your child seems somewhat awake (eyes open, crying out “Mommy!”), she does not recognize or respond to you. She may not want to be held or comforted.
Sleep terrors are common in young children and are related to sleepwalking. Children often have both, usually toward the beginning of the night. They last just a few minutes (but may feel much longer to a parent!).
Because your child is asleep, she does not remember being upset the next morning. Sleep terrors do not mean that your child has had any type of traumatic (upsetting) experience.
The most common trigger for sleep terrors is not getting enough sleep. This is because our brains try to make up for lost sleep by increasing the amount of deep sleep during the night. Since sleep terrors (and sleepwalking) happen during deep sleep, this increases the chances that your child will have a night terror.