Sorry but the entries for James and his wife don't appear to add anything new from what you already know:
10798 TWEEDIE, James, ca 1797-14 Mar 1860. From Torthorwald, DFS. To Fredericton, NB, 1821; stld Caverhill, York Co. Shoemaker and farmer. Wife Margaret Byers, qv, with him and son. SG xxxii/2, 64.
891 BYERS, Margaret. From DFS. To York Co, NB, 1821. m 22 Nov 1819, James Tweedie, qv. SG xxxii/2, 64.
Jacquie