Liz Sheridan, known for playing Jerry Seinfeld's mother on Seinfeld, died on April 15. Sheridan had just turned 93 earlier this week.

Sheridan was born in 1929 in New York. During the 1970s, she started being cast in Broadway musicals and plays, including 1977's Happy End with Meryl Streep and Christopher Lloyd. She quickly worked her way into Hollywood and began appearing in shows and movies such as 1997's Kojak, 1982's Jekyll and Hide...Together Again, 1985's Santa Barbara. She had additional appearances in shows like The A-Team, Who's the Boss?, Hill Street Blues, Remington Steele, It's a Living and others throughout the 1980s.

In 1986, Sheridan first appeared on NBC's ALF. She played Raquel Ochmonek, the snoopy and impatient neighbor to the Tanner family and their cat-eating alien who was constantly dropping by unannounced. Sheridan appeared in over 30 episodes of the show in the following years, her final ALF appearance being 1990's "Gimme That Old Time Religion."

In 1990, Sheridan made her first appearance on Seinfeld as Helen, Jerry Seinfeld's somewhat overprotective but lovable mother. Her first episode, "The Stakeout," was the episode of Seinfeld to air. Sheridan continued to star in over 20 episodes of the show and appeared in all nine seasons of the show up until 1998's final episode, "The Finale." Other iconic episodes she appeared in include 1991's "The Pen," 1995's "The Kiss Hello," 1996's "The Shower Head," 1997's "The Little Jerry" and 1997's "The English Patient."

Along with Seinfeld, Sheridan also voiced the reoccurring character of Mrs. Stillman in the animated series Life with Louie during the 1990s. She continued acting after Seinfeld had wrapped, appearing in shows like Noah Knows Best, Complete Savages, Numb3rs and American Dad. Her last credited role was in a 2010 film called Trim.

Along with acting, Sheridan was also a trained dancer and a singer. She was additionally an author who wrote an autobiographical novel, Dizzy & Jimmy: My Life with James Dean: A Love Story, published in 2000. The novel chronicles Sheridan's experience with a then-unknown James Dean and how the two of them formed a romantic relationship for a time in the early 1950s. She was formerly best friends with Bewitched star Elizabeth Montgomery.

Sheridan's death comes just a week after Estelle Harris -- who played George Costanza's mother, Estelle Costanza, on Seinfeld -- died at the age of 93. Sheridan is survived by her daughter and son-in-law.