Ashman was born in Johnstown, Pennsylvania, on 23 November 1912 to parents George Osborne Suppes and Marion Dibert. Her paternal grandfather, George Plitt Suppes, owned most of the land in that area before it underwent development. Her father was the first president of Johnstown Bank and Trust.

Ashman graduated as valedictorian from both Cochran Junior High School and Johnstown High School. In 1934, she graduated cum laude from Bryn Mawr College. She met her future husband, Wilbur M. Ashman, who would later become the head administrator of what was then known as Conemaugh Valley Memorial Hospital, on the tennis courts behind her house. In 1936, the two were wed and subsequently had three children: George S. “Jeff” Ashman, Sara “Sally” Cifrese, and Thomas W. Ashman. While her husband managed the medical facility, Ashman devoted many years to volunteering there.

Ashman lived independently until she reached the age of 100. She and her husband used to spend their winters in Naples, Florida, but as her husband passed away and she grew older, the travel became challenging. Therefore, she resided in Florida year-round until 2012 when she relocated to Idaho Falls, Idaho, to live with her daughter.