The Billie Jean King Cup was supposed to be a retirement party for Danielle Collins — her last event before saying goodbye to tennis and hopefully starting a family. Instead she arrives in Malaga to represent the United States having decided to prolong her career. Collins deals with endometriosis, a condition in which cells similar to those which line the uterus grow elsewhere in the body. In the lead-up to her proposed retirement, medical experts told her that her endometriosis would mean it wo