Liz Sheridan, the actress who play Jerry Seinfeld’s loving mom for nine seasons, has died from natural causes at the age of 93, according to multiple reports. Sheridan reportedly passed in her sleep in New York City around 2:30 a.m. Friday. In addition to her role as Helen on Seinfeld—which she worked on since the beloved sitcom’s inception—Sheridan starred in a dozen Broadway plays and took on the role of Mrs. Ochmonek on the TV show Alf. Sheridan had a romance with actor James Dean in the 50s, which she wrote about in her 2000 memoir Dizzy and Jimmy.