As Faye has told you, I have done extensive research on the family of Joseph M. and Sarah May Salyards. To answer your query, I do not have any information on Sarah's parents or her siblings.
I worked with the wife of one of the descendants who had done extensive research on the family and she did not have that information either.
I did write to a possible church of their marriage but they did not have a record.
A number of years ago, a woman theologian by the name of May joined the faculty of our local divinity school. The article about her said that she was from that Shenanadoah, Rockingham Counties area. I stopped by one day and chatted with her and she contacted one of her relatives but that person did not have information on Sarah May.
If you have a need for other information on this family then feel free to contact me. You can obtain my Email address by clicking on my name above.
A number of years ago, I posted a summary of various Virginia Salyards families. You can see it by clicking on the following URL: