Sharon Magness Blake (née Costello, born 1950) is a philanthropist and Arabian horse breeder who lives near Denver, Colorado. Born in Philadelphia, Pennsylvania, she was the oldest of James and Esther Costello's six children. She is the widow and second wife of Bob Magness (1924-1996), founder of Tele-Communications Inc. (TCI). Their first meeting involved business dealings and a common interest in Arabian horses. Bob Magness and his first wife of 36 years, Betsy, were active in the business of breeding and racing Arabian horses in the early 1980s which is when they first met Sharon Costello. She was working as sales manager for an Arabian horse breeding operation. Betsy conducted most of the business transactions with Sharon over the course of about 4 years. Sharon later started selling e