Hi Rachel,
William was her husband. He was born 1831 in Bewcastle.
A Robert Armstrong was her father. I found the Canonbie Kirk Session documents which name both him and Charters.
Charters Jackson went on to marry William Armstrong b1831 (same person as above) and had 3 children. Agnes's step brothers & sister. Sarah b1863, Thomas b1865 & William b1866.
When Charters died in 1869 Agnes married William at Gretna Green - again have lots of documents as proof.
Think we have lots to compare so good we are contacting each other privately.
Judy