My husband's great grandmother was Rosannah Shasteen born in VA and probably a sister to your Robert who was the father on William.At least that seems to be the case as his family stayed in Ross Co.
Rosannah and Mary Shasteen Ewing moved to Defiance Co. along with some of the other Shasteens and she had a son Andrew Jackson Shasteen.If the family stories are correct, she was captured by the Indians and Andrew was the result of this.The two women and Andrew when he became an adult and married, moved to Beaver Co., PA.
We have been to Ross Co. and met Martha and visited Defiance Co. twice for research.Hope to get back again in the Fall.We have also done research in VA.
Have you ever figured out who the Martha was that shows up on tax records, census etc.
I have very little on your part of the family and would appreciate anything that you can add.
Sorry that I am so late in answering but we have been traveling. Ruth