Caitlyn Jenner opened up about her parenting experience with the Kardashian sisters during her marriage with ex-wife Kris Jenner. The 73-year-old former athlete revealed that she did her best raising the famous sisters following the death of their dad Robert Kardashian.The media personality shared some sweet words during Khloé Kardashian’s birthday and talked about her time with the family, after marrying Kris in 1991 and becoming a stepparent to Kim, Kourtney, Rob, and Khloé, until her divorce in 2013.“Happy birthday,“ Caitlyn wrote on Instagram.