Who is the mother of Sarah Caroline Couch (1856-1927)?

According to the death certificate received as a digital image from Family Search, Sarah Caroline Couch born 2 October 1856, Rome, N.Y. died 4 July 1927, Joliet, IL.Further information lists her father as Elisha T. Couch, N.Y. and her mother as Angeline Hempton, N.Y. The informant is Mrs. W.J. Schuler (Nettie Couch). Carrie is the informant's aunt. The purpose of this search is to verify the name of Elisha's wife and the mother of Carrie. 

• WI, Eau Claire County. Marriage certificate. George H. Couch and Mrs. Mary E. Fish. Volume 2, page 59.  10 December 1883. George names his father as Elisha Couch and mother Jane Denham. 
• IL, LaSalle County, Probate for Sarah C. Couch, alias Carrie S. Couch. Started 4 June 1928 filed 5 March 1929. In the will, Eugenia Couch Woodin, states that Carrie's parents were Elisha T. Couch and Jane A. Couch. Neither of her parents were married more than once. 
• IL, LaSalle County. Death Certificate for Eugene Couch. 4704. Father's name is Elisha Couch of Hartford, CT. Mother's name is Jane Dunham of Rome, N.Y. informant Mrs. Eugene Couch (wife).
• IL, LaSalle County. Marriage certificate. Lewis A. Couch and Susannah R. Kimberk. 655. 31 October 1883. Lewis names his father as Elisha T. Couch and mother Jane A. Dunham.
• IL, Will County, Death Certificate for Lewis Augustus Couch. 46886. Father's name Couch of New Haven, CT. Mother's name Jane Angeline Dunham of Rome, N.Y. Grace Couch is informant and daughter.

Hempton connection:

William Hempton (1826-1904) married Louisa Dunham (1834-?). I am unable to connect them to my direct line.

After completing the request form to Family Search for Sarah Caroline Couch (1856-1927), I received the digitized copy of her death certificate. According to family records, her mother’s name is Jane A. Dunham Couch. The index name is Angeline Hempton. The death certificate name is Angeline Hempton. The informant in 1927 is my maternal grandmother, Mrs. W.J. Schuler or Nettie Couch Schuler, the niece of the deceased. Carrie went into the hospital for an appendix and gall stone operation and died of a heart attack. This one document has started the search for other family documents. After searching land records, marriages, death certificates and other family records, the only conclusion at this time, is that Nettie was under stress due to Carrie’s unexpected death on 4 July 1927. Only the complete record will reveal all the information. Only the comparison with other records has led me by analysis to conclude that Angeline Hempton is not the mother of Sarah Caroline Couch. Aunt Carrie’s mother is Jane Angeline Dunham, the same mother for all children of Elisha T. Couch.