Tombstone Tuesday - Wherefore art thou?

I know she died,  that is obvious.  She is not on any of the online cemetery sites.  Ancestry.com shows she died in 1830.  I found her male descendants tombstones photographed on www.nnygenealogy.com .  They are buried in Giddingsville Cemetery, Jefferson County, NY.  Why isn't she?

This started me thinking..perhaps she was living with a daughter and not a son.  If this is the case, I may be looking in the wrong state or county.  According to the history book I found, she and her spouse moved to Rupert. VT.

This is what I know from Ancestry.com:

Persis 1754 - 1830

Simon 1/24/1752 - aft 1803 

Children:
          Solomon Graves 1781 - 1858
          Simon Graves 1782
          Joseph Graves 1784 - 1866
          Sarah Graves 1786
          Benoni Graves 1788
          Ira Graves 1790 - 1870

From other resources there was also a son named Jesse.  There being only one known daughter, finding her married name is my next step.

From the DAR application the following children are listed, with spouses if known.

Hannah - Elisha Mack, Salmon, Simon Jr, Joseph, Benoni, Ira, Jesse, Sarah, Susan - Townsley, Submitte - John Converse, Electa, David, Persis - Nathan Underhill.

Source for this information is stated as "Graves Family" book  in the library at Fair Haven, Rutland Co., Vermont.   The last child, Persis, was recorded as born 4/01/1804.  Her mother, Persis, would have been 50 years old.  It is unknown when Simon Sr. died nor where.

Starting with the youngest child, Persis Underhill, wife of Nathan.  I found one Nathan Underhill in the 1830 census in Dutchess County, NY.  There is a burial on Find A Grave for a Nathaniel Underhill, but his wife is listed as Hannah Vail.

Checking for Submitte, there is only one John Covers in the 1830 census.  He is living in Charlestown, Middlesex County, Massachusetts.  Nothing was found for Submitte or John Converse on Find A Grave for this county in Massachusetts.

This is one of those moments that I wished I liven in New England!  Fair Haven Library: (802)265-8011

I scheduled this to post on 1/08/13 and it didn't post until 1/10/13.  Go figure!