Mary Grace Gossage was Thelma Lou's cousin from out of town. She was portrayed by actress Mary Grace Canfield. When she called to say that she would be coming in town, Thelma Lou told Barney that if they were to go the dance, that they would have to find a date for her. However, both Barney, & Andy were reluctant to do so, because they thought of her as less than attractive. So they got her Gomer Pyle, someone that both Thelma Lou, & Helen Crump, had the same feelings about him, as Barney & Andy did about Mary.