Dede is the oldest and only surviving Mirabal sister. For much of the time, it seems of the four daughters, Dede is the least committed to the revolution. Dede "had always been the docile middle child, used to following the lead … Miss Sonrisa, cheerful, compliant. Her life had gotten bound up with a domineering man, and so she shrank from the challenge her sisters were giving her." As Dede tells her story to the American interviewer, she reviews mistakes, choices and her purpose in life. ultimately, she understands that it is up to her to keep the memories of her sisters and their fight for freedom alive.

Minerva, the third of the four girls, is the most colorful of the butterflies, and she is the most committed to anti-Trujillo activities. Minerva tries to enlist all of her sisters in the battle to wrest control of the Dominican Republic from the dictator's vise-like grip. She is outgoing, charismatic...and sometimes impulsive. As the novel progresses, Minerva learns to curb her passions and channel them into the greatest good for her people.

Patria is the second daughter. She is distinguished from her sisters through her religious devotion. However, Trujillo's cruelty, combined with the death of her baby, shake her faith. She is able to return to her faith, not blindly, but with a maturity of mind after she finds purpose in the movement.

Maria Teresa is the baby of the family, nine years younger than Minerva. She seems like she is the most superficial of the girls, caring intimately about her appearance. However, when she is imprisoned, Maria Teresa proves her that she too is worthy of the Mirabal name. Her young life is cut short, along with Minerva's and Maria Teresa's, so we never know just how much she might have done for her people had she lived.