Hettrick was born in Pavilion, Genesee County, New York, USA, on 28 September 1906, to parents Earl Starr (1874–1967) and Luella Milligan (1886–1970). She had four siblings: George Jasper Starr (1908–1989), Mildred Lydia Railing (1910–2000), Lorena Holman, and Florence Moulton (1922–1994). Her paternal grandfather was Noah Starr, one of the earliest farmers in the county, who acquired his farmland from the Holland Land Office. She was born and raised on the property, in a farmhouse constructed by her father in 1890.

In 1926, she graduated from Pavilion Central School and later obtained a dietitian certificate from the Mechanics Institute (RIT) in Rochester. At some point, she married Walter I. Hettrick (1903–1976). The couple had three children: Wendell Hettrick (1935–2014), Ronald Hettrick (1940–1940), and Jane (married Milholland). She was a member of the First Baptist Church of Pavilion. In her earlier years, she served as a dietitian at Homestead Hospital in Homestead, Pennsylvania. Later on, she worked in the cafeteria at Pavilion Central School while also dedicating herself to homemaking.

Hettrick passed away at the Genesee County Nursing Home in Batavia, Genesee County, New York, USA, on 25 December 2016, at the age of 110 years, 88 days. She was survived by her daughter, 4 grandchildren, 9 great-grandchildren and 1 great-great-grandchild.