I could not find the marriage in my Northumberland marriages up to 1837 or the irregular border marriages from the newspapers.
I did find some info on Luke Skelly.
I found 2 Luke Skelly burials in Alnwick St. Michael's:
Luke Skelly, age 77, buried 5 Apr 1872, of Cannongate
Luke Skelly, age 91, buried 30 Nov 1852, of Washburn
Most likely some relation: burial Thomas Reveley Davison Skelly, infant, buried 30 Nov 1854, of Cannongate.
No Isabella Skelly burial in my transcript for St. Michael's.
Marriage of Luke Skelly, bach and Eleanor Reavely, Sp, both of this parish by banns, wit Thomas Walker and John Cameron, 7 June 1796
From the baptisms of Luke junior's brother George (2nd son) in 1798 said that Luke sr and Eleanor were both native's "of this parish", Luke was a Husbandman when son Luke born, shoemaker by 1801, when the 3rd son, John was baptised Luke was a shoemaker. Then in 1807 when the first daur Catherine was born he was a Husbandman again. In 1810 for daur Mary--back to shoemaker.
There were several other Skelly males marrying in the early 1800's
Sorry I couldn't help with the marriage.
Janis