Throughout the series, Carly and Spencer sometimes mention or hint at members of the Shay family.
Carly and Spencer's Relatives
Granddad Shay
Main article: Granddad Shay
Granddad Shay talking to Carly in iWanna Stay With Spencer
Granddad Shay is the grandfather of Carly and Spencer Shay and Ozlottis and Faye Dorfman and also the father of Colonel Steven Shay and the husband of Gramma Shay.
He lives in Yakima, Washington. He usually visits his grandchildren, Carly and Spencer.
His first appearance was in iWanna Stay With Spencer, when he wanted to take Carly to the city of Yakima after Spencer caused her to almost get hit in the head with a hammer. After several failed attempts to change his mind, he allowed Carly to live with Spencer when Spencer revealed he had kept Carly's asthma inhaler "just in case" although Carly hadn't had an asthma attack for years. In this episode, it was also mentioned that he didn't agree with Spencer's choice to become an artist. He also appeared in iBreak A World Record.
Colonel Steven Shay
Main article: Colonel Steven Shay
Colonel Steven Shay is Carly and Spencer's father. He is a Colonel in the U.S. Air Force and currently on a tour of duty in a United States submarine somewhere near Anchorage, Alaska. It has been implied he may be in some kind of classified work. This is assumed because Spencer mentions to Carly in iWon't Cancel The Show, that she probably shouldn't give away their father's current position.
Dan Schneider, the producer of iCarly, cleared up the confusion about if he was in the Navy, or in the Air Force; he was in the Air Force on a Navy Submarine (This makes sense, as the U.S. Navy does not have Colonels, since the equivalent Officer rank in the U.S. Navy is Captain).[1]
He is also known to have an attitude towards Spencer when he is talking on the phone (such as when Spencer was talking to him about Oystomato and he said he didn't care).
Spencer still hadn't told him that he dropped out of law school, according to iSpace Out and iMeet The First Lady.
He calls Spencer and Carly in iStill Psycho to make sure they are okay after being kidnapped by Nora Dershlit (he saw it on the news).
The plot in iMeet The First Lady revolves around Sam and Freddie trying to help Carly stay in touch with her father on his birthday because he is not able to make it home as planned.
He appeared in the series finale, iGoodbye, to take Carly to a special father/daughter dance. During an iCarly webcast held in the episode, he finds out that Spencer dropped out of law school. Spencer later asks him to send more money.
Mrs. Shay
Mrs. Shay is the mother of both Carly and Spencer Shay. Nothing is known about her, as the creator, Dan Schneider, tends to leave out details of absent parents. During a YouTube video of Jerry Trainor, when he was asked where Carly and Spencer's mother was, and he responded, "I don't know, shopping I guess," while laughing.
In the episode iStakeout, Mrs. Benson says to Spencer, "Spencer, you have a stain on your shirt, go put on a fresh one!". Spencer then replies, "But you're not my mother!"
Some fans think that she is deceased, but no information about her has been given out. Another possibility is that she and Steven Shay might be divorced, which may be from separation due to him being in Air Force, or Carly and Spencer's parents were never actually married.
It's also entirely possible that Carly and Spencer could be paternal half-siblings--meaning they have the same father but different mothers, which would also be a logical explanation of why there's such a large age difference between Carly and Spencer.
Nevel questions the absence of Carly's mother in the Sam & Cat episode, #SuperPsycho, but Sam just walks away.
Gramma Shay
Gramma Shay is the paternal grandmother of Carly and Spencer Shay. She is never mentioned on the show.
Great Grammy Shay
Great Grammy Shay is Carly and Spencer's deceased great grandmother. Her diamond encrusted watch was destroyed in a fire in iGot a Hot Room and Spencer got $82,000 for it. He spent it all on Carly's new room. Apparently, Carly and Spencer didn't attend her funeral.