From Chris Dunham, 28 Aug. 2013 on MaineGenealogy:
I believe that Harriet's mother was Sarah W. Hill of Biddeford, whose second husband was also named Hill.
 Sarah W. Hill of Saco, wife of William Hill, bought land in Greenwood of Noah Tobey, 2 Oct. 1846 [Oxford (Eastern District) Deeds, 77:461]. She sold this land on 26 Aug. 1874 to Sarah A. and George H. Wentworth, children of Alfred Wentworth of Bethel, in consideration of "the love and good will" she had for them [195:284].
Sarah W. Hill of Biddeford sold a nearby piece of land in Greenwood to Alfred Wentworth of Bethel, 17 Jan. 1881 [196:535].
 Sarah was born about 1796 in Massachusetts. Mrs. Sarah W. Hill married 1835-36 in Biddeford Capt. William Hill. I haven't found the name of her previous husband, who presumably was Harriet's father.
 From a transcription of gravestones at The Oaks Cemetery, Biddeford:
Hill, Mrs. Abigail, d. 3 July 1807, aged 67.
Capt. William, d. 14 April 1863, aged 78 yrs. 11 mos.
Lorana, wife of Capt. William Hill, d. 29 May 1835, aged 47 yrs.
Sarah W., wife of Capt. William Hill, d. 5 Oct 1883, aged 86 yrs. 8 mos.
Paulena [sic], dau. of William and Lorana Hill, d. 5 May 1873, aged 62 yrs.

https://www.findagrave.com/memorial/167561199/lorana-hill

Per Chris Dunham 28 Aug. 2013:
“Oh, now I see who Sarah was. I had her in my notes all along. She was Sarah W. Tobey (probably Sarah Wildes Tobey), daughter of Noah and Abigail (Gilpatrick) Tobey of Topsham and Greenwood. She was born 27 Feb. 1797 in Topsham. She married first (intentions published 23 Jan. 1819 in Biddeford) Daniel Hill of Biddeford, who must have been Harriet's father. The Tobeys and Wentworths were neighbors in Greenwood, which might explain how Harriet came to meet Alfred.”

Named for her maternal grandmother, Sarah (Wildes) Gilpatrick.

Birth recorded (no name) in Pastor’s Record, 1789-1810 (Film #007834729) @ FHL, images 10/22.
Noted as 27 Feb. A Daughter to Noah Tobey and Wife.

Children of Noah Toby and his wife Abigail recorded in Greenwood, Oxford Co., ME, vital records: https://www.familysearch.org/ark:/61903/3:1:3Q9M-C...i=119&cat=349881

Note the “typos” here:
Nathaniel listed as born August 2, 1895 [sic]
Sally listed as born 27 Feb 1878 [sic]
Noah Gilpatrick born 18 Oct 1807
Nancy Tapley Dustin born 24 Nov 1811
Silas Dutton born 28 Jun 1815

Last name listed as “Toby” in marriage intentions in Vital Records of Biddeford, ME (p. 284) (NEHGS).

It seems that Daniel and Sarah must have moved to Boston after their marriage. Sarah signs for deposits for Eliza B and Harriet M in the Providient Institution for Savings bank on 25 March 1829. Both Eliza B and Harriet M are listed as minors.

Deposit records in Waste Book 4C, 1821-1833, pg. 200/506, available from NEHGS/AmericanAncestors.org.
https://www.americanancestors.org/databases/boston...=297&filterQuery=

The signature for the deposits indicate “Eliza B Hill and Harriet M Hill signed by Sarah W Hill,” in Boston Athenaeum digital collections Signature Book 2, image 279/473
https://cdm.bostonathenaeum.org/digital/collection/p16057coll55/id/5640/rec/2

Eliza B not found on Boston birth OR death records.

There is a deposit for Sally Hill, “married,” made on 9 January 1828, signed for by William Gray. Other “Sally Hill” deposits are for a mantua maker earlier than this date.

Marriage to William notes as follows:
March 17 [1835]
Capt. William Hill of Biddeford and Mrs. Sarah W. Hill of Boston have this day entered their intentions of marriage with me. Edmund Coffin, Town Clerk.
[Note: this date is weird—Lorana didn’t die until May 1835. Check. — Stet, but yes, it should be 1836]
https://www.familysearch.org/library/books/viewer/432441/?offset=0#page=132

Biddeford Book of Records #5, Intentions of Marriage. FamilySearch film. (Image 260/532)
https://www.familysearch.org/ark:/61903/3:1:3QS7-L...i=259&cc=1803978

In A Complete List with Index of Births, Deaths, Marriages as Recorded in the Biddeford Town Records, bk 5, marriage date to “Capt. William Hill” is listed as 9 May 1836. (Image 264/532)
https://www.familysearch.org/ark:/61903/3:1:3QS7-L...i=263&cc=1803978

See also: https://www.familysearch.org/library/books/viewer/432441/?offset=0#page=136

Notice in the Boston Courier (Boston, Massachusetts), Monday, May 16, 1836; Issue 822, pg 4: “In Biddeford, Me. Capt. William Hill to Miss Sarah W. Hill, of Boston.”

Family listed on 1840 USC for Biddeford, ME:
M<5 = 1 = Ezra
M 10-14 = 1 = Jonathan Ward
M 20-29 = William Jr.
M 50-59 = Capt. William
F 15-19 = Harriet
F 40-49 = Sarah W.

Where are William’s other daughters (who reappear on the 1850 census)? This would suggest no other [surviving] siblings for Harriet (other than half-brother Ezra).

Sarah W is living with son Ezra at time of 1870 USC for Biddeford, ME.
Living alone at time of 1880 USC for Biddeford, ME.

In Oxford County Deeds, Bk 195 pg. 284, Sarah W Hill of Biddeford, in consideration of the love and good will I have for Sarah A and George H Wentworth, children of Alfred and H M Wentworth of Bethel, County of Oxford, and state aforesaid, I do hereby grant, bargain, sell and convey…the lot of land numbered five (5) in the eighth (8) range of lots in the town of Greenwood…containing 100 acres more or less. Dated 22 Apr 1880.

William Hill is a “Capt.” specifically. Can more info about him be found? Probate/Will? Did Sarah leave a will?

Sarah was the administratrix for Capt. William Hill’s probate (Docket 9404 available on FamilySearch.org:
https://www.familysearch.org/ark:/61903/3:1:3QS7-8...37101&cc=2094226

Heirs listed at the time of probate (Mar 1873):
Nehemiah Hill — Biddeford
Paulena Hill — Biddeford
Lorana Hill — Biddeford
Sarah A Littlefield — Wells
Caroline [Hill —] Wells
William Hill — Biddeford
J Marie Hill — Biddeford — this one is tough to read as the letters in Ezra’s name overlap
Ezra Hill — Biddeford

No will was included in this packet, and no will found for Sarah W herself.

Sarah is listed on the Biddeford and Saco, Maine Directory 1875-76 as “widow of William” with the address of “Pool Rd, near Ferry Lane.” Ezra is listed above as “ship master, house Pool road.” Many other Hills are listed as being on Pool Rd.

https://www.findagrave.com/memorial/167561186/sarah-w-hill

Continuing forward:
I checked the Boston Directories from 1818-1837. If Daniel and Sarah were “of Boston,” they should show up here, including Sarah in her widowhood (if that’s what happened).

Sarah never appears at all.

There are Daniel Hills. The one(s) who list as housewrights continue to be listed after 1837, so they seem to be out of the running as contenders. There is a Daniel Hill, Capt., mariner, listed as living “rear of 10 1/2 Center St.” in 1821 and a Daniel Hill, capt. on Sun-court St. in 1825, who I suppose could still be viable—if he’s the same person both times--he doesn’t appear after 1825 (notable as it’s the same year as Harriet’s supposed birth).

But Sarah doesn’t remarry until 1836, and that’s a big gap. And if she were widowed and living in Boston, she should have been listed in the directory, I would imagine, as other widows do.

This makes me think that even as she’s listed as being “of Boston,” she was perhaps not living IN Boston during this period. This would also explain why neither Harriet nor Eliza B are listed in Boston birth records. Maybe she was living in a nearby locality that was conveniently near enough to Boston that she “rounded up,” if you will.

Unfortunately, this means that although the Provident Institution for Savings deposit records, which were so exciting last week, I’m no closer to identifying these folks this week. The search continues.