Volz, Olga, Head, aged 43, widowed, immigrated 1881, alien, born Russia (Russian), parents b. same Volz, Augusta, Daughter, aged 22, single, b. New York, operator, telephone co. Volz, William, Son, aged 17, single, b. New York, clerk, insurance
Olga and Philemon were married in 1895 in New York in Manhattan. Getting a copy of the marriage record may provide more information, and if they were married in a church, that should provide additional information.
Olga died in the Bronx on 1 July 1945, aged 69 years. Her death certificate may also prove useful.