I wasn't familiar with the term "Flappers", so for anybody else wondering i got this from history.com:
Flappers of the 1920s were young women known for their energetic freedom, embracing a lifestyle viewed by many at the time as outrageous, immoral or downright dangerous. Now considered the first generation of independent American women, flappers pushed barriers in economic, political and sexual freedom for women.
No one knows how the word flapper entered American slang, but its usage first appeared just following World War I.
The classic image of a flapper is that of a stylish young party girl. Flappers smoked in public, drank alcohol, danced at jazz clubs and practiced a sexual freedom that shocked the Victorian morality of their parents.