For a discussion of the children of James Stevens and both wives, go to http://home.fuse.net/oxley/oxley.htm
and find the article on the children of Hannah Oxley.
James Stevens married Hannah Oxley about 1770, not 1762, she was his second wife.
By his first wife, he likely had -
Ann, Zachariah, Benjamin, Elizabeth, William, & Mary.
by the second wife he had -
James, Hezekiah, Henry, Alice & George.
Zachariah and Benjamin had left Loudoun Co. by 1800 apparently. I'm not sure about the rest. They were all of age in 1798 when James Sr. died.