Actress/comedienne Sheryl Underwood has spent her life haunted by the death of her twin sister. The star, who is now a co-host on U.S. chat show The Talk, opened up about the childhood tragedy during an episode of the show on Friday (13Sep13), revealing her mother gave birth to premature twins and one did not survive. Underwood insists the loss of her sister has affected her her entire life and even altered the course of her career, saying, "You know, people ask comedians, 'Where does the funny come from?' and for me, it comes from my desire to never have anyone feel what I felt through my childhood and certain periods of my life... I was born a twin, and we were premature. We were both in the incubator. What you don't know is I carry her birth certificate around because she did not live." The star also reveals her childhood was blighted by her parents' strained relationship and allegations of domestic violence, adding, "My birth mother did not want me and my father to be close to each other, so she would tell me that my father killed my sister... I love my father - but I did not get very close to him until one day, I saw my mother stab my father. A lot of people have domestic violence in their families, a lot of people witness a lot of things, so to get through that, I started to engage my sister, my twin, as my guardian angel."