Island of the blue Dolphins is a story based on a factual event. The children's book tells a story of an Indian girl who lives a very happy life but, with the arrival of White men finds her life turned around. As so often happened, the White men are greedy, rough men who care only about making money. They argue with the tribe, kill most of the men and sail away. The survivors do their best until another group of White men arrived and took the survivors away. But her little brother is left behind, so she jumps overboard to swim back and save him.
Why nobody ever comes back to get the two of them, I don't know. But he is eventually killed by the wild dogs of the island and she is left completely alone. In order to survive she makes friends with the wild dogs even though they killed her brother. She learns to do things that were forbidden to women by her tribe, like making weapons and hunting. Supposedly the spirits forbade women from doing these things. But if she didn't do them, she would starve. After many years, she is found and rescued. The story ends in the book as she is sailing away from the island feeling happy and safe.
The lessons here are that people, in order to survive, have to face unexpected and surprising things. Sometimes they're good sometimes they're bad.
She has to change her former beliefs and find new ones. It isn't good to believe that everything will always be as it is. You must be prepared for the future and you must be willing to change precious beliefs in order to survive. It, in many ways, is a harsh lesson but the way the book is written, events end up with her being physically saved and, in effect, finding spiritual salvation and heading to a new life. So in spite of all the suffering, it is an acceptable children's tale that ends happily.
Good lessons. Although rather hard ones. Not all parents want their children to be made to give up precious beliefs in order to survive or adapt to changes. Still, the book is popular among left-wing liberal circles.
Sadly, life had a different ending. Six or seven weeks after her rescue her saviors, who were friars, reported that she was a wonderful, happy girl who delighted everyone around her. This did not protect her. She caught dysentery and died only a few weeks after her rescue.
So the real story ends up sounding like something written by a modern existentialist. You know, life is horrible, brief and then you die. Sartre would write it, or Kierkegaard, or one of those other grim philosophers.