Justina presumably lives in Adventure Bay with her father Gustavo and fraternal twin brother Julius. She frequently appears with her brother as a background character. She and Julius are often seen playing with Alex and the other children, or participating in local events like the Adventure Bay's Easter Egg Hunt or competitions like Frog Jumping Contest.
Justina is much like her brother. Her and Julius usually say things in unison when they have speaking roles.
Justina has brown skin and brown eyes. She has short brown hair with 2 pigtails; one on each side. She wears a purple T-shirt with a flower on it. She also wears blue pants and purple shoes.