The 54-year-old had been rushed to hospital straight from a rehearsal for 8 Simple Rules For Dating My Teenage Daughter.
The final series, its title trimmed down to 8 Simple Rules, ended in 2005, having won a cinematography Emmy in 2004.
The Charmed actress captioned her photo, 'A little #8simplerules reunion party today with a tiny addition �� @kateylous @martinspanjers @amy_davidson #lennoxsawyerlockwood (someone is smiling down on us)!
'That 'someone' referred to John Ritter, who played the patriarch of the programme's central Hennessy family.
He hates his job, his wife is lazy, his son is dysfunctional (especially with women), and his daughter is dim-witted and promiscuous.
In several episodes, characters drink "Safeway Select" colas.
Though the sitcom revolved around Ritter’s character, it was ultimately decided to keep the show going and Ritter’s character dies off-camera. When he calls, Ed’s ready to get sexy with her over the phone but she has to hang up.
The next few episodes deal with his loss and how the Hennessy family moves on. Bridget was supposed to be in charge of the Ditch Day prank, in which she was to steal a rival school’s goat mascot.
The show's premise and title were derived from the book 8 Simple Rules for Dating My Teenage Daughter: And Other Tips from a Beleaguered Father (Not That Any of Them Work) by W. The third season (after Ritter's death) took a creative turn, revolving more around cousin C. (David Spade) and grandfather Jim (James Garner), than the immediate Hennessy family, more specifically not revolving around the raising of the Hennessy girls.
On Thursday, she uploaded an Instagram photo of herself reuniting with the original cast of the ABC programme 8 Simple Rules For Dating My Teenage Daughter - except, of course, for the late John Ritter.
Her black-and-white snapshot showed the 30-year-old leaning into frame and grinning broadly alongside Katey Sagal, who played her mother, as well as Martin Spanjers and Amy Davdison, who played her younger siblings.
After entering a hiatus, the series continued without Ritter, incorporating the death of his character.
James Garner and David Spade joined the cast afterward.
It debuted on ABC on September 17, 2002, and concluded on April 15, 2005.