Born October 21, 1887, Mary Jane Behmer was the daughter of Samuel H. Behmer (1852-1913) and his wife, Mary Jane Landis (1855-1936), residents of Lancaster, Lancaster County, Pennsylvania at the time of the 1880 census. Their children were Kate and Morris, the latter actually named Maurice.

By 1900, the family lived in Juanita, Blair County, Pennsylvania. Kate and Maurice were no longer in the home. The children were Dora, Mary, Chester, Lucy, and Clarence.

On November 1, 1907, Maurice Behmer was killed.

Still in Blair County in 1910, the Behmer children were Dora M., Mary S., Chester W., Lucy A., Clarence and Ada.

At the time of the 1920 census, Mary Behmer, a trained nurse, was a roomer at a house on Windsor Street, Pittsburgh. In 1927, Mary J. Behmer was a nurse at Carnegie Steel Company in Homestead, Pennsylvania. In 1930, still at Carnegie Steel, she was a renter in West Homestead. She was a resident of Wellington Apartments, Melwood Street, Pittsburgh, at the time of the 1940 census, and the record indicates she had had lived there in 1935. She was still a nurse in the steel industry.

Mary Jane Behmer, retired nurse, died August 23, 1951, at Williamsport Hospital, Williamsport, Lycoming County, Pennsylvania, according to her death certificate. She is buried at Grandview Cemetery, Altoona, Blair County, where her parents are also interred.