After years of studies and investigations by the Sacred Congregation for the Causes of Saints in the Vatican, the pope can approve the canonization of the person as a saint.
It is called Canonization.
Canonization is the process of declaring a person to be a saint.
Saint Anne was declared a saint in 1584. She is the grandmother of Jesus Christ as her daughter was Mary.
No rock singer has been declared a saint
Saint Francis of Assisi was declared a Saint on July 16, 1228, perhaps the quickest canonization in the history of the Church - less than two years after he died
No, she has not been declared as a saint.
Pope John Paul II declared Juan Diego a saint.
Technically, someone has to be dead to be declared a saint.
Mother Teresa has been beatified but not yet declared a saint.
No, she is not yet a saint but she was declared venerable in 2010.
For an excellent biography of Saint Ambrose that will explain why he is a saint, click on this link.
St. Jude was not declared a saint by a pope. The canonization process did not exist at the time. he was declared a saint by the early Church because of his martyrdom.
Constantine is only considered a saint in the Orthodox Church and was not canonized or declared a saint in the Catholic Church.