The Girl Scouts series was written by Millie under her own name of Mildred A. Wirt. This series involves members of the Beaver Patrol who have adventures and solve mysteries on their outings. There were only three volumes in this series:

• volume #1 The Girl Scouts at Penguin Pass, 1953
• volume #2 The Girl Scouts at Singing Sands, 1955
• volume #3 The Girl Scouts at Mystery Mansion, 1957