Two princesses in a pod
How do you teach someone to be a good friend? There are so many factors: likability, common interests, circumstance. Sometimes it happens by chance, other times it's cultivated. Some friendships are short and serve a purpose. Some are life-long and foundational. Many can be just for fun and joy. In this situation the friendship is strengthened by the love of Elsa and her fabulous wardrobe!
I think about the fact that I know how to make friends. I just don't know how to keep them around. But then I remember that I married my best friend and through all the various phases of love and romance, anger and frustration, we've still managed to remain good friends.