This is not Hannah Powers as many have believed. See my notes on Thomas Farr Sr. or the notes on Hannah Whitcomb.
Thomas Stanley Farr sent me a copy of a 1915 hand written genealogical chart compiled by Lawrence Brainerd of Chelmsford, Massachusetts which states that Hannah Farr daughter of Samuel Farr married her 1st cousin Thomas Farr Jr. I've been looking for the maiden name of Hannah wife of Thomas Jr. since figuring out that her maiden name was not Powers. (See notes on Thomas Farr Sr.)
At first I couldn't swallow this assertion but the more I studied it the more it looked possible. In looking at Samuel Farr's will, we find the following: Item: I give to my three married daughters what I gave them viz. Hannah Farr, Elizabeth Whitney, & Hepsibah Thomas......... He names his daughters by their married names and this includes Hannah!
Next I looked at the vitals that I had on Hannah Farr daughter of Samuel Farr and all the information I could find online about her. Everyone has her being born about 1732 and married to Samuel Hildreth on the 27th of November 1759. I also have her marriage documented with an original source. The problem I saw with the marriage year of 1759 was the fact that Samuel Farr's will was dated 1754 thus putting Hannah's marriage well before 1759 and obviously not to Samuel Hildreth. The parentage of the Hannah Farr that married Samuel Hildreth is now not known. This now puts the birthdate of Hannah Farr the daughter of Samuel Farr much earlier than 1732 and at least in the neighborhood of 1720 in order to be named as a married daughter in a will dated 1754.
This makes it possible that Hannah Farr daughter of Samuel Farr is the Hannah that was married to Thomas Farr Jr. the son of Thomas Farr Sr. The Samuel Farr we have been talking about here is the brother of Thomas Farr Sr. thus Brainherd's chart labeling Hannah Farr as a 1st cousin and wife of Thomas Farr Jr. The chart also points out that Dr. William Farr married his 1st cousin Jemima Farr. Dr. William Farr was a son of Jonathan Farr brother of Thomas Farr Sr. and Jemima Farr was a daughter of Stephen Farr Jr. also a brother to Thomas Farr Sr. This information we already had correct.
Whether or not this is correct about Hannah Farr being the wife of Thomas Farr Jr., it is correct that Hannah Farr daughter of Samuel Farr is not the one that married Samuel Hildreth, her birth was much earlier and her married name was "Hannah Farr"!
Since writing the above, it was brought to my attention by Vanessa Herring that the Hannah Farr who married Samuel Hildreth was a daughter of Daniel Farr and Leah:
I have an interest in Samuel Hildreth who married Hannah Farr, since my James Wheeler became guardian of several children in that branch of the Hildreth Family. I came across your research on the various Hannah Farrs, and realized that I have the answer to your question of which Hannah Farr married Samuel Hildreth of Westmoreland NH.
The answer lies in a quit claim deed that was executed in Chesterfield NH and Boyleston MA in 1787. The following persons of Chesterfield participated in the quit claim: Samuel Hildreth [wife Hannah possibly having died before/during 1787], Daniel Farr, Edward Hildreth and wife Sarah [nee Farr], and Mary Farr. Patience Farr of Boylston MA also participated. For the sum of 5 lbs, each, they quit claimed to Samuel Farr of Boylston MA their interest in the estate of "our hon'd father Daniel Farr late of Shrewsbury North Parish, now called Boylston, deceased".
So, the Hannah Farr who married Samuel Hildreth was an unrecorded daughter of Daniel Farr and Leah Unknown. Neither the date nor place that Daniel married Leah are known, but Hannah must have been born around 1741/2, though she is not recorded in Stow.