New evidence has surfaced since I made this post over a year ago, that might help narrow down where Emily is interred and roughly when she died; as such, I figured it best to revive this thread with this new information. It's not much, but it's something.
It's possible that Emily's parents were James McClain and Nancy Shropshire; there is a birth record from nearby Bath County that corroborates the roughly correct age, giving her birth date as 24 March 1856. As I cannot find any records linking this Emily Royse with that specific Emily McClain, it is simply speculation at this time.
Emily McClain was married to John Wesley Royse on 20 December 1877; the marriage took place in Rowan County, but apparently a courthouse fire destroyed the record. John mentioned it specifically in his application for pension for his service during the Civil War, and further gives the name of Rev. Rufus Humphrey as the man who officiated the wedding. A cursory search turns up that Rufus was associated with the New Hope Primitive Regular Baptist Church in Cranston; as such, and considering there are other Royse family members interred there, it's possible that's where Emily is buried. John additionally re-married after Emily's death, to a woman named Rosey Conn, maiden name Reed; as there are a few Conn family members buried in the same cemetery, this further cements the possibility.
John's marriage to Rosey occurred 20 May 1906; this leads me to believe that Emily died between the 1900 US Census and this date. Considering Emily was John's second wife, married shortly after his first, Martha Ann Wilson's death, it seems more likely that Emily's death occurred in either 1905 or early 1906; however, it really could have been as early as 1900, given the dearth of any official records.
John Royse himself, having passed in 1918, was buried at Slaty Point, as mentioned in the previous post; his sister, Rebecca "Becky" Cook, is also interred there, which makes me think that he and the family may have been members of that congregation at one point. In that case, it's also possible that Emily is buried there as well. While she was not John's final wife, she was, by far, the longest-lived and longest-wed, so it would make sense that the two of them might have been buried together. As I cannot seem to get ahold of the Slaty Point Baptist Church, I cannot confirm or disprove this possibility as of yet.
Please, any help that might be available from anyone who might know anything would be greatly appreciated; Emily, being my 2nd-great grandmother, is my closest brick wall at the moment, and it would be very meaningful just to know where she was laid to rest, much less when she died.