Born in San Francisco, California as Lenore Gilmartin, she had a twin sister, Joan Gale (née Lorraine Gilmartin; born September 13, 1912 – June 11, 1998), along with another set of twin sisters, Jane Gale (née Helen Gilmartin; born July 6, 1911) and June Gale (née Doris Gilmartin; July 6, 1911 – November 13, 1996), although they were not quadruplets, as has occasionally been misreported.

[2] Jean's elder sister June wed Oscar Levant in 1939, to whom she remained married until his death in 1972, and by whom she had three children.

This brought Jean to the attention of studios, and led to a small role in the film Bottoms Up (1934), starring Spencer Tracy.

She only had four film roles following the baby star moniker: Kiss and Make-Up, Young and Beautiful (both in 1934), a third in A Star Is Born (1937), and the fourth, Girl from Avenue A (1940), all of which were uncredited.

She settled in Los Angeles, where she was residing at the time of her death on September 26, 1974.