In the Massachusetts Town Clerk Town Records, 1627-2001 for Suffolk County Boston, we find the death record for nine month old George G Shackford whose relative is listed as the Widow Shackford. The cause of death is listed as canker which may have been the term used for the disease of thrush according to an article called What Did They Call it When They Died? .
We are fairly certain that George G is the son of Thomas Greenleaf Shackford (Levi Shackford's first son) and his second wife Elizabeth Ganzlar who he married on February 12 1824. We haven't found a record of George's birth yet but are fairly confident that he was their son born about January 1825. The listing of the relative as Widow Shackford was because Elizabeth had recently become a widow -- Thomas had died of intemperance in June 1825.
It must have been a tragic time for Levi and Tamison - losing their son in June followed by the loss of their grandson three months later.
SOURCES
Hannan, Nancy H., “What did they Call It When They Died? A Study of the Listed Causes of
Death in the Town of Hyde Park, Massachusetts, 1869-1900” Historical Journal of
Massachusetts Volume 32, No. 2 (Summer 2004)
"Massachusetts, Town Clerk, Vital and Town Records, 1627-2001," digital images, FamilySearch (http://familysearch.org : accessed 2 August 2014), Jane Shackford d. Sept 24, 1822
"Massachusetts, Marriages, 1695-1910," index, FamilySearch (http://www.familysearch.org : accessed 2 August 2014), Thomas Shackford m Jane Macclward 11 May 1817.
Massachusetts, Massachusetts, Town and Vital Records, 1620-1988, , George G Shackford d. of canker, 15 September 1825; digital images, Ancestry.com (http://www.ancestry.com : accessed 2 August 2014); Town and City Clerks of Massachusetts. Massachusetts Vital and Town Records..