Mary's son, adam, is two years old. if mary falls down and hurts herself, adam most likely will then mimic her. At the age of two, child will most likely follow everything he sees. Everything is right at the eyes of the child. Expressing emotions is healthy, although they aren't happy ones. You can also inform your child that they can also be unhappy sometimes. Be careful also of your actions and using of words.
Many primary sources cannot be understood because of the language or they way they have written it. We can't always understand it because its from a culture completely different from our own. Reading primary sources requires your his historical imagination.