<Li> Ben Truman, Will and Vince's son, is played by Ben Newmark . Appearing only during the series finale, Ben was apparently born from a surrogate mother using Will's sperm . Upon going to college, he meets and later marries Grace's daughter, Laila . </Li> <Ul> <Li> Stanley "Stan" Walker, Karen's third husband (little is known about her first two), is a mostly unseen character . He is an obese man, and has worn a toupee since his teens . Stan has two children from a previous marriage to a woman named Kathy . Karen fell in love with him in the 1980s but they didn't marry until 1995 . Stan was jailed for tax evasion in season four, and began an affair with a cafeteria worker named Lorraine (played by Minnie Driver), and--after his release in season five--continued the affair, ultimately separating from Karen because of it . He is reported to have died at the end of season five but, at the end of season seven, he reveals to Will that he had faked his own death and is hiding out with the aid of the government . He and Karen reconcile in season 8, but subsequently faced marital difficulties and divorce . Stan's popularity with fast food establishments leads to Pizza Hut taking out a full - page ad in the New York Times to congratulate him on his release from prison; Taco Bell also organize a flyover at his funeral . It is revealed in the series finale that Stan's riches were actually borrowed and that he had no real money of his own . </Li> <Li> Mason Walker, Stan's son, is another unseen character . He is known to Karen as "the fat one". During one episode, Karen visits Mason during a swim try - out . She cheers and applauds and has a conversation with him until, at the end, she realizes she has been conversing with the wrong boy and not Mason after all . </Li> <Li> Olivia Walker, Stan's daughter, is played by Hallee Hirsh . Although she has had fun times with Karen, such as sticking food to the floor to see how long Mason will spend trying to eat it, she also has problems with her stepmother . </Li> <Li> Lois Whitley, Karen's mother, played by Suzanne Pleshette . A con artist who used Karen in her early schemes . They had been estranged for several years when they reconciled in season 4, with the help of Jack . </Li> <Li> Virginia "Ginny" Delaney, Karen's sister, played by Bernadette Peters . In 1963, as a child, she was injured in a brutal game of Twister played with Karen . </Li> <Li> Barry, Karen's cousin, is played by Dan Futterman . Originally a gay bookish homebody, Karen had Will and Jack bring him out of his shell to become an attractive person whom both Will and Jack fall for . </Li> <Li> Sylvia Walker, Karen's mother - in - law, is played by Ellen Albertini Dow . She is a woman that' strikes fear in her heart - facsimile' . A seemingly kind, but homophobic old woman, Sylvia appears in one episode to accompany Will and Jack to a club . In the beginning neither Will nor Jack wanted to babysit Sylvia, known as "Syl". She had been dumped on them by Karen, who then ditched her . Karen and Syl have a caustic relationship . </Li> <Li> Sumner, Karen's nephew, is played by Paul Satterfield . Karen tries to keep him from dating Grace in season 3 . </Li> </Ul> <Li> Stanley "Stan" Walker, Karen's third husband (little is known about her first two), is a mostly unseen character . He is an obese man, and has worn a toupee since his teens . Stan has two children from a previous marriage to a woman named Kathy . Karen fell in love with him in the 1980s but they didn't marry until 1995 . Stan was jailed for tax evasion in season four, and began an affair with a cafeteria worker named Lorraine (played by Minnie Driver), and--after his release in season five--continued the affair, ultimately separating from Karen because of it . He is reported to have died at the end of season five but, at the end of season seven, he reveals to Will that he had faked his own death and is hiding out with the aid of the government . He and Karen reconcile in season 8, but subsequently faced marital difficulties and divorce . Stan's popularity with fast food establishments leads to Pizza Hut taking out a full - page ad in the New York Times to congratulate him on his release from prison; Taco Bell also organize a flyover at his funeral . It is revealed in the series finale that Stan's riches were actually borrowed and that he had no real money of his own . </Li> <Li> Mason Walker, Stan's son, is another unseen character . He is known to Karen as "the fat one". During one episode, Karen visits Mason during a swim try - out . She cheers and applauds and has a conversation with him until, at the end, she realizes she has been conversing with the wrong boy and not Mason after all . </Li>

Who plays vince's sister on will and grace