The Brownie Scout series was written under Millie's own name of Mildred A. Wirt and consisted of these 6 volumes:

volume #1 The Brownie Scouts at Snow Valley, 1949

volume #2 The Brownie Scouts in the Circus, 1949

volume #3 The Brownie Scouts in the Cherry Festival, 1950

volume #4 The Brownie Scouts and Their Tree House, 1951

volume #5 The Brownie Scouts at Silver Beach, 1952

volume #6 The Brownie Scouts at Windmill Farm, 1953

This series involves a Brownie Scout Troop and their leader, Miss Gordon, who takes the girls on outings, camping trips, and even to the circus.