Liz Sheridan, best known for playing Jerry Seinfeld's mother in the hit eponymous sitcom, has died just days after celebrating her 93rd birthday. The veteran actress died in her sleep overnight of natural causes in New York City, her longtime friend and manager Amanda Hendon told Deadline and NBC News. Her death was confirmed by Jerry Seinfeld in a tweet who called Sheridan "always the sweetest, nicest TV mom a ...