 Mengering's maternal grandparents, Fredricke Hilgediek and William Strietelmeier, were born in Germany, and her father was of German descent.A younger brother, Earl Jr. (1922–2009), and sister, Hazel (1923–2017) who died at age 93, less than three months after Mengering, were born respectively.Dorothy's first cousin is the grandmother of the model and actress Rebecca Romijn, a fact which was discussed on the "Late Show with David Letterman".