A: Your toddler's brain undergoes some significant changes around the age of 3. This includes sleep changes -- and, unfortunately, nightmares often make their first appearance at this age. To make it more complicated, she's not at an age where she understands the difference between "dreams" and "reality."
Comfort and reassure her. Tell her you understand she had a bad dream, that something scary happened, but you're with her and will keep her safe. Over time, she will start to understand the difference between dreams and reality. Until then, offer repeated reassurance. Try some sleep-easy rituals for preschoolers, like "Monster Spray," which can work wonders. Fill a spray bottle with water and use it to spray away the scary dreams before bed each night. Let your daughter use the spray, too, to chase the monsters away.