Iam playing peekaboo with one of my infant daughters and her favorite toy. i hide it under the blanket. she laughs and pulls the blanket off, finding the toy. she is demonstrating which of piaget's stages?

The correct answer is the sensorimotor stage of cognitive development. 

According to Piaget's theory of cognitive development, she is in the sensorimotor stage of development. During this stage of cognitive development-which occurs at age 0-2 years in infants- infants develop something known as object permanence. This means that infants develop the ability to understand that objects continue to exist even if they are hidden from them or no longer in view. 

object permanence

Explanation:

Devotion. attachment. fondness. love. passion. these are all synonyms to each other.