Isn't she Jon Stewart's mother?
Stewart grew up in Lawrence Township, New Jersey with his parents, Marian and Donald Leibowitz. His mother is a physicist and his father is an educational consultant. He unofficially dropped his last name, Leibowitz, and altered the spelling of his middle name from "Stuart" to "Stewart." While he often jokes this is because people had difficulty with the pronunciation of Leibowitz or it "sounded too Hollywood" [1] (a reference to Lenny Bruce's joke on the same theme), Stewart has implied that the name change was actually due to a strained relationship with his father, who left the family in 1971 and with whom Stewart no longer has any contact [2]
I'd be surprised to find out that Lynne Stewart produced children.