The death certificate of a distant cousin, who lived most of her life in Pittsburgh, describes her occupation as "maiden." A cursory search of the net has provided no answer. Best guess at this time suggests maiden to be a polite term for servant.
The lady, whom I'll call Mary since that's her name, lived from 1862 to 1943 and came from a family of means. She never married. I suspect the money ran out and she became "employed" by a minister and family for approximately the last 15-18 years of her life.
Anyone have the answer?