Is princess sultana al saud alive?

Yes, the princess mentioned in the Jean Sasson book "Princess", named Princess Sultana is still alive.

Most recently the author shared with readers on a blog that she recently met with Princess Sultana in 2013 to discuss a new book that will be another true story about the princess, due out in 2014.

(Note: if you're referring to the older Saudi Princess, named Sultana bint Abdulaziz Al Saud, she was born in 1928 and passed away in 2008.)