Well, you will probably need to follow this through a bit more, but it would appear Thomas J Harper and Mary Virginia got married about 1900 or so if Waif was the first child. Although he was born in MO, it's possible they slipped across state/county line to get married.

What information do you have saying Mary Virginia's maiden name was Smith? The reason I ask is because her daughter Lillian, who died in California, states her mother's maiden name as Tillman.