Friendship at 4 is innocent. It is requests to play with her best friend and greeting each other with excitement and a giant hug. Even when they fight about which toys to play with and they don't always want to share they do not stay upset for long.
Friendship at 4 is moving easily between groups of friends. It is realizing that we see some friends at preschool, some at church, and some around our neighborhood but making no distinction. These friends are not "better" than those friends.
Friendship at 4 is playing with friends even when they are not around. The dolls and play people receive the names of her friends or she talks to them on her play cell phone. Friends are not forgotten when she plays alone.
I will be saddened when she reaches the age where friendship is no longer so innocent. I watch the young teen girls in our neighborhood and see how they turn on each other so quickly over misunderstandings. They travel in packs and leave the weakest behind or, even worse, run them off. I know that eventually the loss of a friendship for whatever reason will cause her pain and that is a pain I wish that I could help her avoid.