Miriam Allen was born about 1742. She and Robert Merriam were married on 24 Jun 1762 in Tyringham, Berkshire County, Massachusetts. Robert died in 1782 at about 44 years of age.
Miriam died in 1808, aged 66; her grave is in Woods Cemetery, Monterey, Berkshire County, Massachusetts.
Except for Place of Birth and residence in 1800, the source for all information is Merriam Family Tree. FindAGrave posits Miriam was born in Lexington and "was residing in her household in New Marlborough (now part of Pittsfield), Berkshire, Massachusetts for the 1800 Census (see summary below)."
1800 Census summary: 1 free white male age 16-26; 2 free white male, age 26-45;
1 free white female, age 26-45; 1 free white female, age 45 and over [Miriam]
1800 Census -- "United States Census, 1800," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XHRZ-LBK : accessed 29 May 2019), Miriam Merriam, New Marlborough, Berkshire, Massachusetts, United States; citing p. 236, NARA microfilm publication M32, (Washington D.C.: National Archives and Records Administration, n.d.), roll 13; FHL microfilm 205,611, page 236.
FindAGrave; link here:  Full source citation: Find A Grave, database and images (https://www.findagrave.com : accessed 29 May 2019), memorial page for Miriam Allen Merriam (1742–10 Aug 1808), Find A Grave Memorial no. 32552127, citing Woods Cemetery, Monterey, Berkshire County, Massachusetts, USA ; Maintained by cindy hoogs (contributor 47080584) .