Bridget Agnes Brandle was born January 22, 1905, in Missoula, Montana. She was the daughter of Michael and Mathilda (Faas) Brandle. Following the death of her father, she was placed in an orphanage in St. Paul, Minnesota, while her mother worked outside the home. She was adopted by her step-father, William Quirk, after he married Mathilda Brandle.

She attended high school at St. Benedict's in Collegeville, Minnesota, and continued her education at St. Alexis Hospital in Bismarck, North Dakota. She graduated as a registered surgical nurse and followed that with one year of training in massage. She married Frank J. Wetch and the couple moved to Thief River Falls, Minnesota. They operated Frank's Eat Shop, a small café, as well as the Northern Hotel. They later opened the Wetch Hotel, which Agnes Wetch operated until 1989. Frank and Agnes Wetch had two children: Gerald and Mary Ann.

She married Ole Hegtvedt on August 18, 1979, in Thief River Falls. Agnes Wetch Hegtvedt died February 19, 1990, in Thief River Falls.