Mary's memorial falls under an uncommon unknown burial aka lost to history. She died in Switzerland, Indiana, but her grave site wasn't recorded, nor does she have a marker.

Circumstantial/corroborating evidence is extremely strong and it all points to Mary being a daughter of Lewis and Tryphena....there is a daughter her age on the 1800 Herkimer Co, NY Census in Lewis' HH. She and her husband are listed in census records next to or near the other Hinmans in 1820, 1830, and 1840 and so on. The 1850 and 1860 Census list her birth place as New York. A land sale between her and Arnold Hinman, and the other Hinman siblings, in Switzerland County, Indiana insinuates that the land was a transaction related to an inheritance from their father Lewis. The deed also gives Polly's maiden name as Hinman. Lorenzo Dow Hinman, son of Andrew and Tryphena and 1/2 brother of Polly, moved to Camden County, MO. as it turns out, Polly's son Henry Marvin Calkins moved to Camden Co, MO also. Additionally, Parker Bradford, a son of Roxanne Hinman Bradford, also moved to Camden Co, MO for awhile and married a sister of Henry Calkin's 2nd wife.

Switzerland County
Will Book 3 1859-1877 pg 148 (partial)
Last Will and Testament of Mark Calkins
...I Mary Calkins of Florence Switzerland County in the state of Indiana do make and publish this my last will and testament. Item 1st. I give and devise to my grandson James A. Calkins all my real and personal estate. Subject however to the payment of all my just debt out of the rent and profits of my Real Estate. And should my daughter Zamira Robinson ever again be left a widow then and in that case it is my will that she shall occupy the dwelling house wherein I now reside without charge during her widow. Said James A. Calkins is not to have the management and control of the Real Estate above described until he arrives at the age of twenty three years (23). Item 2 I do hereby nominate and appoint my esteemed friend Lemuel Bledsoe my executor unde this my last will and testament directing him to dispense with appraisement and sale of my personal estate dated this April 22, 1867. Mary Calkins Signed and Acknowledged by said Mary Calkins as her last will and testament in our presence and signed by us in her presence. John Orem and William Land

1867 Dec 26 Vevay Reveille "Notice is hereby given that the undersigned has been appointed Executor of the last Will of Mrs. Mary Calkins, later of Florence, Switzerland County, Indiana. Said Estate is supposed to be solvent. Dec 19, 1867. L. Bledsoe, Executor."

1820 Hamilton, OH Census August 7, 1820
James Colkins-Same pg as John Dunn & Arnold Hinman

1830 Switzerland, IN
James Calkin

1840 York, Switzerland, IN
James Calkin-next to Oren Bradford & Lewis Hinman

1850 Census Massac, IL,
[listed next to sons Henry M. and William P.]
Ferdinand Eggleston 26 b. KY
Zemirah Eggleston 16 b. IN
Mary Calkan 50 b. NY
William Rody 28

Henry M Calcan 28 b. IN
Elizabeth Calcan 22 b. KY
Sarah Calcan 2 b. IN
Mary Calcan 1 b. IN
William P Colcan 18 b. IN

1860 Florence, Switzerland, IN
Ferdinand Egleston 36 b. KY
Zemira Egleston 25 b. IN
James Calkins 8 b. IL
Mary Calkins 61 b. IN

Jerome Reynold Calkins:
"The History and Genealogy Of A Branch of the Calkins Family", vol 1, pg 22.
Children of Thomas Calkins and Mary Hindman are:
William Calkins b. Abt. 1819, South Bend, St. Joseph, IN; d. Unknown
Orn Calkins b. Abt. 1821, South Bend, St. Joseph, IN; d. Unknown.
Henry Marvin Calkins b. October 24, 1822, Switzerland Co, IN; d. July 23, 1910, Montreal, Camden, MO

Note: some of the info in the book is not correct

Note: Information in the Camden County Missouri Historical Society contributed by a family member indicates that Mary's husband was Thomas C. Calkin. But Mary's will indicates it's James A. Calkin: "Thomas C who married Mary Hendman--Mary Hinman."