Hello,
I am also researching this family...

Daniel F. Johnson's Newspaper Clippings at PANB has the following...
December 7, 1893 County : Saint John Place : Saint John Newspaper : The Daily Sun - Caven Lanstroth BETTS was born in St. John in 1853 and was educated at the Grammar School and Normal School. For a time he taught in Westmorland Co. and then he removed to New York to pursue his literary calling. He has been residing in the eastern metropolises for 16 years. He is now a member of the editorial staff of the 'Youth's Companion'.

PANB birth records - ROBERT HARGRAVES LANGSTROTH (M), CRAVEN/GAVEN LANGSTROTH, FRANCES BETTS, 18 November 1843, FRENCH VILLAGE, KI

Also NB First Families records
Frances Purdy Betts born 25 Nov 1806, married Craven Longstroth
she was sister of Hiram born 22 Jan 1809, buried 13 Jun 1878 in Saint John, m. 4 Apr 1838 at Saint John, Sarah Ann Purdy

Nova Scotia Marriage Bonds - Date: 04 April 1838 Hiram Butts Sarah Anne Purdy Co-signed by Samuel Purdy

NB First Families records them as children of Hiram Betts born 4 Mar 1773 at White Plains, NY, d. 10 Jun 1850 in
Saint John, s/o Azor Betts and Glorianna Purdy: he came to NB in 1783 with
the Loyalists: later moved with his parents to Digby in Annapolis County, NS,
then came back to NB and settled in Saint John: m. 21 Aug 1796 at Digby, NS,
Elizabeth Craig b. 15 Jan 1772 at Oakham, MA, bur. 26 Feb 1851 Saint John,
d/o James Craig and Mary Houlton

NB First Families also records the descendants of Ephraham who is the one that most interests me...

Ephraim Betts probably born in Connecticut, died before 1847, m.
Sarah Wheeler d/o Zalmon Wheeler of Fairfield County, CT: family came to
NB in 1783 as Loyalists: first settled in Fredericton, York County, then moved
to Bettsburg, Ludlow Parish, Northumberland County by 1795:
Children are listed in an estimated order:
1) possibly, Ephraim Wheeler Betts b. - , d. before Nov 1817, married 1801
Rachel Munro d/o Evan Munro of Maugerville: had four children:
2) Jared Betts b. c1786 m. 1834 Ann Clouston and had issue:
3) David Betts born 1789, died 9 May 1872 at Derby, NB: m. and had at least
eight children:
4) William Betts b. 1793, d. Sep 1817:
5) Benjamin Betts b. 1798:
6) Azor Betts:
7) Samuel Betts b. 1801:
8) Nelson Betts b. 1807:
One source lists additional children:
9) King Betts:
10) Sarah Betts m. Mr. Bartlett:
11) Hill Betts b. 1806, d. 1892 in ME:
12) Levi Betts.

Hill Betts born 1806 who died 1892 is my ancestor except he did not die in Maine...

(May 5, 1892 County: Kent Place: Richibucto Newspaper : Review d. Main River (Kent Co.) 18th April, William Hill Z. BETTS, 86 year)

WILLIAM HELKIAH JACKSON BETTS born about 1806, NB., married MELICENT "MARY" ATKINSON b: 23 NOV 1794 in Ft. Lawrence, NS Baptized Feb 22, 1830 or born about 1811, NB., (She died before 1881)