I've found two different marriage years for Susannah and Nathaniel on ancestry.com. One is 1766 and the other is 1796 (see below). One of the marriage years could be an indexing typo or there are two men named Nathaniel Raines married to two women named Susannah Parham. Or possibly the names were indexed incorrectly. I haven't seen an original marriage record for them. On the website Descendants of William Raines, their marriage year is given as 1755 in Brunswick County, Virginia. Besides Ann, their children are listed as Hartwell, Frances, Mary, Nathaniel, and Susannah. This website indicates that Nathaniel served as a Captain in the Revolutionary War and gives his death year as 1789 in Virginia.
I didn't find a record for a Captain Nathaniel Raines on fold3.com, but I found a Nathaniel Raine (without the 's'). One service record says "Nathaniel Raines" and that it is "filed with Nathaniel Raine." The pension record for Nathaniel Raine notes that he has a wife but doesn't give her name. This Nathaniel Raine served as a Corporal with the Virginia Regiment during the war and was living in Kentucky at the time he filed for a pension in 1819. I don't think this is the same person as my Nathaniel Raines.
As with many of my ancestors, I need to do more research to find out more about Susannah.
This post is part of the 52 Ancestors in 52 Weeks challenge by genealogist Amy Crow at No Story Too Small.