Have you tried this site:
http://rosdavies.com/SURNAMES/C/Cromie.htmDo any of these assist you:
Surname(s) Graveyard Civil Parish Graveyard Location County
Cromie, Rathfriland R.P. Drumballyroney Rathfriland Down
Gravestone Inscription Alexander [no dates given], also Joseph Cromie, theology student, died 14/12/1888 aged 26
Surname(s) Graveyard Civil Parish Graveyard Location County
Cromie, Rathfriland 1st Pres Drumgath Rathfriland Down
Gravestone Inscription James, of Drumaiken, died 06/10/1859 aged 23, also Elizabeth Cromie, died 06/12/1879 aged 60 and Mary Cromie, died 10/03/1880 aged 23
Surname(s) Graveyard Civil Parish Graveyard Location County
Cromie, Rathfriland R.P. Drumballyroney Rathfriland Down
Gravestone Inscription William, died 06/05/1887 aged 45 and his wife Anne Cromie, died 02/09/1905 aged 63