Niki de Saint Phalle was born on October 29, 1930 and died on May 21, 2002. Niki de Saint Phalle would have been 71 years old at the time of death or 81 years old today.
To be officially canonized as a saint you must, of course, be dead. However, anyone in a state of grace in Our Lord's eyes, living or dead, is considered a member of the "Communion of Saints.