Born Mary Rosyna Davis in Portsmouth, Ohio, she was of Welsh ancestry and belonged to a musical family. She traveled with her parents and sang at religious gatherings and other events during the 1930s. She earned a degree in music and education at Ohio State University.
She was a member of the university symphonic choir and university chorus, and was a female soloist with the Ohio State Men's Glee Club.
After teaching in Ohio, she moved to New York City, where she studied voice with Frantz Proschowski. She sang on national radio and with orchestra leader Horace Heidt and his Musical Knights and performed with her sister, Ruth, as the Davis Sisters.
After her 1942 marriage to G. Neilson Sigler, a financial consultant, she moved to Baltimore, where she continued her musical work. In the 1950s she sang at St. Thomas Episcopal Church in Owings Mills and at the First Church of Christ, Scientist on University Parkway. She was also a soloist at area synagogues, family members said.
Mrs. Sigler was a member and treasurer of the Baltimore Music Club. She also belonged to the Woman's Club of Roland Park.
A memorial service will be held at 2 p.m. Jan. 7 at Roland Park Presbyterian Church, 4801 Roland Ave.
In addition to her sister, Ruth D. Moyer of Towson, survivors include two sons, John N. Sigler of Timonium and Richard M. Sigler of Baltimore; a daughter, Marylou R. Frey of Orlando, Fla.; six grandchildren; and six great-grandchildren. Her marriage ended in divorce.