Dave First Wife Michelle
In the link or article provide below there is a Photo of a Group of People which includes Jimmy Walker, Dave and Jay Leno.
In the Photo is also Dave First Wife Michelle Cook:
http://www.hollywoodreporter.com/live-feed/jimmie-walker-letterman-leno-memoir-70s-comedy-339404
From 1976
Sitting, left to right: Elayne Boosler, Gene Braunstein, Jimmie Walker, Adele Blue (Jay Then Girlfriend), Jay Leno, Michelle Letterman (Dave First Wife). Standing: Helen Kushnick, Wayne Kline, Budd Friedman and David Letterman.