Before they’re about 15 months old, children don’t show the signs of embarrassment–the blushing, smiling, and nervous touching that often come with this emotion. Between 15 and 24 months, children take big steps in self-awareness and become more aware of themselves as individuals. At this stage children learn that other people have beliefs, desires, and feelings different from their own. When they become more aware of how other people might see them, children are capable of being embarrassed.
Lewis, M. (2000). The emergence of human emotions. In Lewis, M., & Haviland-Jones, J. M. (Eds.), Handbook of emotions (2nd ed.). New York: Guilford Press.