Thankful M. Wilson was the daughter of William and Harriet Wilson of Brakhamsted, Litchfield County, Connecticut. She married Isaac Elwell, in Barkhamsted, on 24 Dec 1845.

The 1880 Nebraska State Census of Greenwood Precinct, Cass County, page 38, includes:
Isaac Elwell, age 60, born CT, Farmer
Chestina Arbograss, age 22, born CT
Phoeba Elwell, age 26, born CT, deaf and dumb totally
Lilly Upson, age 4, born MI
Burton Elwell, age 25, born in CT
Wm Wooldridge, age 50, born in NY, Farmer
Jannette Wooldridge, age 34, born CT
Polly Wooldridge, age 12, born NY
Wm H. Wooldridge, age 10, born NY
Sarah J. Wooldridge, age 7, born NY
Burton E. Wooldridge, age 1, born MI

Isaac Elwell was the father of Chestin (Elwell) Arbograss [Arbogast], Phoeba Elwell, Burton Elwell and Jannette (Elwell) Wooldridge. Chestina is seen in later records as Justena or Justeny, the wife of Josiah Arbogast, who she married 20 Jun 1877 in Lee, Allegan County, MI. Lilly Upson was the daughter of Justena by her 1st husband, Wilbur Upson. This record indicates Isaac's wife, Thankful, died between the 1870 and 1880 census. This family returned to Michigan by 1884 as two of these children, Burton Elwell and Polly Wooldridge married there in 1884.

This census was taken on 24 Apr 1880 and on the next page is a list of births and deaths that were associated with the families listed on page 38. The only entry is on the Registration of Deaths and Causes. Listed there is Thankful Elwell who died in month of February at the age of 60 years from "heart disease". Since she had died in February and the census was taken in April she must have been buried somewhere in Greenwood Precinct of Cass County, Nebraska. I have attached an image of this record. The left hand side of the image records Thankful Elwell's death but the image is very faint.

I have no evidence Thankful was buried in this cemetery as she may also have been buried in the Greenwood cemetery.