Hello Christian, Our family tree contains Kinghorns what info I have may fill a gap or two. James K married Janet Duncan in 1795, tahey had son James. James K married Helen Cuthbertson in 1823, they had1 James, 2 Jean, 3 Janet, 4 Helen, 5 William, 6Hugh,& 7 Marion. 1 James K married Agnes Anderson in 1886, they had James, Agnes, Helen, Agnes, William, Hugh, & Marion. 6 Hugh married Eliza Kirk on 20-9-1861 in London,they had 1 Margaret b 1862 London, 2 James b 1-11-1863, 3 William Kirk, 4 James b 21-4-1867 in Leith, 5 Hugh b 21-4-1867 in Leith, 6 Helen Cuthbertson, 7 Donald Archibald MacVean, 8 John, 9 Henry, 10 Frances Alice Jane, 11 Thomas Sewell b 1879.
I can go on further through the seven generations but it will be easier to post them to you if any of these fit your tree.