Have you received results yet? Looking at Mumford Rural Cemetery's records there are lots of McColls, including a Dugald D. McColl, unknown - 29 Oct 1848. There were a couple of Janes but none with your dates -- Jane McColl unknown - 20 Feb 1847 and Jane McIntyre McColl d. 1869 and Jane Ann Wooster McColl d. 1905. Also a few Jennys, as Jenny can be a nickname for Jane, one d. 1861, the other 1938. Since there was a difference of 38 years between their deaths, it's a strong possibility she might have remarried. I'm sure you know Find-A-Grave doesn't list any Dugald McColls buried in Michigan at all - no surprise. I have 2x great-grandparents who lived in Hillsdale County, MI and I've never been able to find their burial location. I think Michigan has a lot of cemeteries not entered, or possible a lot of burials on private farms. I'd be happy to look at Mumford Rural Cemetery here in NY. My daughter lives in the Cal-Mum area & we do a fair amount of grave hunting as we are older, retired, and extremely bored. Let me know if you still need it done and if you have any additional information.