Nana Barberin, biological daughter of Jérôme and Anne Barberin, lives with her family in the rural French village of Chavanon. She possesses deep red hair, mirroring her mother and contrasting sharply with her adopted older sister Remy's appearance.

As Remy's younger sister, Nana exhibits steadfast admiration and loyalty, frequently shadowing her sister and copying her actions. While this devotion sometimes causes Remy minor annoyance, genuine affection binds the sisters. Nana's family loyalty is further evident when she openly confronts her father during his hostile outbursts against Remy, directly challenging his authority to defend her sister.

Her daily life centers on the family's farm, where she actively participates in chores alongside her mother and sister, including tending to animals like the family cow, Rosette, a vital economic asset. Within the Barberin household, Nana's presence highlights the contrast between Jérôme's harshness towards Remy and the maternal warmth Anne provides.

Exclusive to the anime adaptation and absent from the original 1878 novel *Sans Famille* by Hector Malot, Nana Barberin serves to amplify themes of familial conflict and adoption dynamics.