That's my same theory also, which seems to fit real well into the Michael family. Also most people that I have talked to think that I am right about Orpha Michael being Phillip and Mary's daughter.
Since I have found Elizabeth wife of Phillip in Mercer Co., Missouri living with Silas. And Sarah Michael and James Shelton Voiles living in Mercer Co., Mo. also, it lends more credence that Phillip and Elizabeth is the mother of Sarah Michael Voiles, sister of my Ruth Michael Voiles.
One researcher thinks it's possible that Edward Michael could also be a son of Phillip and Elizabeth instead of Phillip and Mary,because they are also in Mercer Co., Missouri but I think that Phillip and Mary's children are Edward and Orpha and Lavinia not (Phillip and Mary had 12 children) Phillip and Elizabeth's. I think that Edward and Orpha are possibly twins. We have a lot of twins from the Voiles and Michael's in my line.