First, the series of postings under this title presumes that Dabney Pettus married Ann Overton. I have previously argued that this is incorrect, and my forthcoming book will provide the evidence to support my position.
I must say that I have done little research on the Browns and have no opinion on whether Thomas Brown of Essex and Thomas Brown who married Mary Pettus of Lunenburg/Mecklenburg were related. That would be an interesting avenue of research. As for John Pettus of King and Queen County, he and Richard Wyatt paid quit rent in 1704 on 800 acres of land in Essex County. Unfortunately, too little information is available on John to say how he was connected to Mary Pettus, if at all.