Fifteen-year-old Bridget Brown had $700 saved and asked a 13-year-old friend where he wanted to go.
The friend, Bobby Nolan III, suggested Nashville.
Together with Brown's 11-year-old brother, the three took a taxicab to Jacksonville International Airport and bought three tickets at the counter. The children say no one asked them for identification.
They called their parents from Nashville and immediately flew home.
Southwest Airlines says the company's minor policy covers children ages five through 11 traveling alone, and that the 11-year-old in this case was accompanied by two older companions.