Marla Gibbs
Leroy Jethro Gibbs's daughter's name was Kelly Gibbs.
She was named 'Boo' by the characters but as far as I'm aware her full character name in the film was never revealed. Speculation is that her name is Mary named after Mary Gibbs, the actress who gave her voice to the part. I remember hearing somewhere that her real name was Mary, but as far as it goes film wise, her real name is never spoken. Sulley nicknamed her Boo, but her actual name is Mary (seen briefly in a picture in the film). The picture with 'Mary' was actually drawn by Mary Gibbs, the actor who played Boo and was incorporated into the film. Boo's actual name may well be Mary though. The Internet Movie Database only lists the character as "Boo". The book based on the film gives her name as Mary Gibbs.
A family friend of Donald Bellisario (Exec. Producer) is called Leroy Jethro Gibbs, so I'm guessing that's where the name came from. I don't think the real-life Gibbs is an NCIS agent though.
No, he only had one daughter (Kelly) and she was murdered
Mark Harmon
Marla Gibbs
Florence Johnston, in 'The Jeffersons' was played by the Marla Gibbs.
Geoffrey Gibbs's birth name is Geoffrey George Gibbs.
Gerald Gibbs's birth name is Gerald Ernest Gibbs.
Irving Gibbs's birth name is Irving Paschel Gibbs.
Rachel Gibbs's birth name is Rachel Danielle Gibbs.
Terri Gibbs's birth name is Teresa Fay Gibbs.
Kelly Gibbs
Leroy Jethro Gibbs's daughter's name was Kelly Gibbs.
While the television show NCIS is based on a real government organization, the character Jethro Gibbs is completely fictional. Mark Harmon is the actor who portrays Gibbs on the CBS tv series.
The last name Gibbs is Scottish. The name Gibbs is from the name Gibb which is a pet name for Gilbert.