This genealogy research gets a little confusing since the same names were used over and over.
You mentioned that James and Margaret Calhoun came to the USA from England in the early 1800's.Was it their son that married Margaret UNK since she was born about 1825 in North Carolina?Was their son named James or John?Sometimes a middle name was used instead of a first name.I noticed that on some of the Census records.
The Margaret UNK maybe Margaret Morrison born in North Carolina.
You noted that Drusilla Calhoun's first marriage was with Wallace Wilson.Was Wallace Wilson Elmira Elizabeth Calhoun's father?
Many thanks to your Aunt Vera for starting this research and to you for continuing with it.