Dorothy Mengering

Dorothy Marie Mengering (July 18, 1921 – April 11, 2017) was an American television personality. She was the mother of late-night talk show host David Letterman. She made many telephone and live guest appearances on his shows: "Late Night" and "Late Show". 
Following several years of appearing through telephone, Mengering (usually known as "Dave's Mom" or "Dave's Mom Dorothy", with no mention of her surname) became a recurring on-camera guest on Letterman's subsequent "Late Show", initially by covering the 1994 Winter Olympics in Lillehammer, Norway. 
In 2015, Mengering suffered a stroke, but recovered months later. Mengering died on April 11, 2017 at her home in Carmel, Indiana at the age of 95. She died one day before Letterman's 70th birthday.