Mike
Going back to the 1851 Census, and with the info re occupation for William, this is the only other option I can see:
BRYDEN Ann, daughter of Margaret Bryden, DRESSMAKER, 35, born Troqueer Kbt
BRYDEN Catherine, daughter of Margaret Bryden, MILLINER, 30, born Troqueer Kbt
BRYDEN John, grandson of Margaret Bryden, SADDLER apprentice, 16, born Dumfries Dms
BRYDEN Margaret, head of household, widow, 72, born Canonbie Dms
BRYDEN Robert, grandson of Margaret Bryden, 11, born Dumfries Dms
BRYDEN Thomas, grandson of Margaret Bryden, PAINTER apprentice, 18, born Dumfries Dms
BRYDEN William, grandson of Margaret Bryden, 14, TAILOR apprentice, born Dumfries Dms
GORDON Marion, boarder in household of Margaret Bryden, ANNUITANT, 81,
born Dumfries Dms
MAREN Helen, SERVANT, 19, b Dumfries Dms
Address: 119 High Street(821), Dumfries
Now to make sense of that family!
Monica