Thelma Harper

Thelma Mae Harper , also known as Mama, is a fictional character played by American actress Vicki Lawrence. She is a senior citizen who has lived in an unspecified part in the Southern United States for her entire life which is evident by the southern drawl of her speech and her customs. Wikipedia*

On the C-SPAN Networks:
Thelma Harper has two videos in the C-SPAN Video Library; the first appearance was a 2000 Convention.