S. E. Hinton is alive, and as far as I know, she is still writing. Her name is Susan, but she used S. E. Hinton on her books because her publisher believed she would have a difficult time selling her books if readers thought she was female. She was born in 1950, in Tulsa, OK, so that would make her 59 years old. She has written several novels beside "The Outsiders." She has also written: "Rumble Fish," "That Was Then This is Now," "Tex," and "Taming The Star Runner," "Hawks Harbor," "Tim's Stories," "Big David, Little David," and "The Puppy Sister."
She has her own website which I have linked below as well as other biographical links. Not only has she written these novels, but she has also been a consultant on the films which were made based on her novels, been a wife, and a mother of one son, Nick.
Hinton wrote these stories because as a young teen she was frustrated with the type of stories available to teens. She was only 17 when "The Outsiders" was published.