Jane Marie Cox was the highschool sweetheart of Kurt Vonnegut, knowing him since kindergarten. After Vonnegut's service during World War II, they married. The two attended the University of Chicago for a while, Jane accepting a scholarship to study Russian.

She dropped out when she became pregnant with the couple's first child, Mark, in 1947. After Vonnegut dropped out, the two relocated to Schenectady, New York, where Vonnegut accepted a job with General Electric. In 1951, the couple had their first daughter, Edith.

After establishing himself as a full-time author, Vonnegut relocated his family to Cape Cod, Massachusetts. In 1954, they had their third child, Nanette, and in 1958, adopted Vonnegut's sister's children after his sister Alice died of cancer, and her husband, James Carmalt Adams, died in the Newark Bay rail accident.

Later in life, Jane embraced Christianity, which put her at odds with Vonnegut, an atheist. These disagreements drove a wedge between the couple, which eventually led to their divorce in 1971. The two remained good friends, however, until Jane's death in 1986.