Elizajb,
Although the 1851 census ( 2416-171-3) has Mary Hunter's " Where Born" as Scotland, the 1861 census (3866-107-5) shows her "Where Born" as
Falstone.
Falstone was a parish, a very expansive one, lying in the corner where the borders of Scotland, Northumberland and Cumberland met. Falstone was a small community lying noth west of Bellingham village.
Several Scottish parishes, within the county of Roxburghshire, bordered the parish of Falstone, e.g. Castleton, Teviotdale, Hopkirk, Southdean, etc. The Cumberland parish of Bewcastle was adjacent to Falstone.
Did you search for the marriage beyond Church of England records. Both the parishes of Falstone and Haltwhistle had Presbyterian churches from mid 1750s.
Michael