Why does Karana’s feelings about enemies change?

In my opinion, Karana's friendship with Tutok changes her feelings about enemies. Intially, she doesn't trust Tutok, but over the course of time, the two girls become friends. When Tutok leaves, Karana misses her company, and is once again left without human companionship. It is many years before humanity returns to the island. Karana is older, more mature, and finally willing to put her fear aside in order to reconnect with the human world. I wouldn't go so far as to say her feelings about enemies have changed completely, but she is willing to expose herself and take the chance.