There is no canonized saint named Kristen. However, the name is derived from the name Christine or Christina and there are a number of saints with those names.
A person of exceptional holiness, who demonstrates a life of almost perfect virtue; the Catholic church would call this kind of person a saint. The official canonization process is: First, you have...
Valentine was a holy priest in Rome, possibly a bishop, who assisted the martyrs in the persecution under Claudius II. He was apprehended and sent by the emperor to the prefect of Rome, who, on...