Wow! I think you may have just given me a clue! I didn't know about the 1885 marriage, but the 1880 census has my Lowery family listed next door to a Collum family. A widowed Margaret is the head, is she the Mary you are talking about?
I haven't been able to find Charles after the 1880 census, but with this information, perhaps I can help to find them.
Please let me know if you have other information or if I can answer any more questions.