Question: Charles Wallace Murray is a major character in a fantasy/science fiction series of how many young adult novels written by Madeleine L'Engle?

Context paragraphs:
Time Quintet: The Time Quintet is a fantasy/science fiction series of five young adult novels written by Madeleine L'Engle.

Edward Nason West: Edward Nason West (1909–1990) was an Episcopal priest, author and canon sacrist at the Cathedral of Saint John the Divine in New York.  He was the inspiration for Canon Tallis in Madeleine L'Engle's young adult novels.  He was a graduate of Boston University and the General Theological Seminary of the Episcopal Church.  He was an Officer of the Order of the British Empire; an Officer of the Order of Orange-Nassau; a Chevalier of the Legion of Honor; and a Knight Commander of the Royal Order of St. Sava.

Charles Wallace Murry: Charles Wallace Murry is a major character in Madeleine L'Engle's Time Quintet series of young adult science fiction novels.  He is first introduced in L'Engle's "A Wrinkle in Time" as the youngest sibling of the protagonist, Meg Murry, and accompanying her on her adventures alongside Calvin O'Keefe.

Troubling a Star: Troubling a Star (ISBN  ) is the last full-length novel in the Austin family series by Madeleine L'Engle.  The young adult suspense thriller, published in 1994, reunites L'Engle's most frequent protagonist, Vicky Austin, with Adam Eddington, both of whom become enmeshed in international intrigue as they travel separately to Antarctica.  The story takes place several months after the end of "A Ring of Endless Light", the novel in which Vicky and Adam first met.

Zachary Gray: Zachary Grey is a fictional character in the young adult novels of Madeleine L'Engle.  He appears in four novels, and is mentioned in at least one more.

Canon Tallis: Canon John Tallis is a major character in the young adult novels of Madeleine L'Engle, appearing in four books.  The character is based on L'Engle's real-life spiritual advisor, Canon Edward Nason West of the Cathedral of St. John the Divine in New York City.

The Moon by Night: The Moon by Night (ISBN  ) is the title of a young adult novel by Madeleine L'Engle.  Published in 1963, it is the second novel about Vicky Austin and her family, taking place between the events of "Meet the Austins" (1960) and "The Young Unicorns" (1968), and more or less concurrently with the O'Keefe family novel "The Arm of the Starfish".  The book marks the first appearance of the character Zachary Gray, who dates first Vicky and then (in later books) Polly O'Keefe.  Although Vicky will later appear in three novels that have fantasy and/or science fiction themes, there are no such elements in "The Moon By Night".

A Live Coal in the Sea: A Live Coal in the Sea, written by Madeleine L'Engle and published in 1996, is the sequel to "Camilla Dickinson" (also published as "Camilla"), one of L'Engle's earliest novels.  While "Camilla Dickinson" was written for a young adult audience, "A Live Coal in the Sea" is an adult novel.  It continues the story of Camilla Dickinson as a college student, her marriage, her family and the problems that follow.  The story is told by an aged Camilla to her granddaughter, who is seeking answers about her family.

Andre Norton Award: The Andre Norton Award for Young Adult Science Fiction and Fantasy is an annual award presented by the Science Fiction and Fantasy Writers of America (SFWA) to the author of the best young adult or middle grade science fiction or fantasy book published in the United States in the preceding year.  It is named to honor prolific science fiction and fantasy author Andre Norton (1912–2005), and it was established by then SFWA president Catherine Asaro and the SFWA Young Adult Fiction committee and announced on February 20, 2005.  Any published young adult or middle grade science fiction or fantasy novel is eligible for the prize, including graphic novels.  There is no limit on word count.  The award is presented along with the Nebula Awards and follows the same rules for nominations and voting; as the awards are separate, works may be simultaneously nominated for both the Andre Norton award and a Nebula Award.

Calvin O'Keefe: Calvin O'Keefe is a major character in Madeleine L'Engle's "Time Quartet" series of books, and, as "Dr. Calvin O'Keefe", an important character in her O'Keefe series of young adult novels.  In an interview released on the DVD of the TV adaptation of "A Wrinkle in Time", L'Engle describes Calvin as "the boy that we all, all us girls want to meet.  Not all of us are lucky enough to meet a Calvin, but I was.  And I married mine."

Supporting paragraphs: Charles Wallace Murry Time Quintet
Answer: five