This photo was a studio portrait taken at Prawitz in St. Joseph, Missouri, on February 7, 1935. It commemorates Mrs. Lyon's "golden anniversary as organist".
A little online digging revealed that Mrs. Mary Rich Lyon was the long time and celebrated organist at Christ Episcopal Church in St. Joseph.
Mrs. Lyon was born Mary Hannah Corrine Rich to parents Moses and Helen (Hinsdale) Rich in New York in 1858. About 1880 she married to David Canfield Lyon and the couple had 3 children: Ada, Helen and Richard. Mrs. Lyon was widowed before 1900 and is found in several censuses in St. Joseph, Missouri, through the most recently available one of 1940. She is sometimes shown with the occupation of "music teacher" and sometime as "organist". No record is found of her death, but a newspaper article published when she was in her 80s mentions that her daughter Helen is coming in to live with and take care of her.
Other interesting tidbits surfaced as I was wandering around the Internet, including the fact that her mother Helen published a volume of poetry and her daughter Ada was a career woman who made a name for herself as society editor of the St. Joseph Daily Press for over 50 years.