As noted, this cemetery is located on Hyde Road, Greenbush Twp, Clinton County, Michigan.I happen to have the cemetery transcription, which is available from the Elsie Historical Society, (see http://www.rootsweb.com/~migratio/elsiehiso/elsiehistsoc.htmlhttp://www.rootsweb.com/~migratio/elsiehiso/elsiehistsoc.html ).It is a relatively large cemetery compared to some of the other booklets that I have in Clinton County.
There are 6 Lockwood family members listed, Elizabeth, Enoch, Ernie W., Igola, Mary E., William R.Nothing is noted about the parents of Enoch or Elizabeth.There are no "Mummy" names in this cemetery transcription.
However, in the North Star Cemetery, Elba Twp., Gratiot County, transcription, there are "Mummey" names.They are Melissa Eleanor (1884 - 1954) and Welcome A. (1876 - 1945). No other information is given.
To find parents, you may want to look in cemetery transcriptions of Indiana, in the area where they lived.You may try looking at Census records, and then look at usgenweb, selecting Indiana, then the counties.
Good luck and I hope this gives you some information.
Jack Sheldon Mesa, Arizona (formerly of Owosso, MI)