Stef is a strong, protective, and sometimes strict police officer. She is married to Lena and is Brandon's biological mother. She deeply loves her family and is willing to fight for them.

Lena is Stef's wife and the other mother of the family. She works as a school vice principal and is compassionate, patient, understanding, and emotionally supportive.

Brandon is Stef's biological son and Lena's stepson. He is talented at piano and music, intelligent, caring, and ambitious. He often gets caught up in complicated relationships and family drama.

Callie is Jude's older sister and eventually becomes Stef and Lena's adopted daughter. She is independent, rebellious, brave, and emotionally complex. She struggles with her past in foster care while trying to find a place where she belongs.

Mariana is Jesus's twin sister and one of Stef and Lena's adopted children. She is smart, outspoken, fashionable, artistic, and sometimes impulsive. She cares about her friends and family, even when she makes questionable decisions.

Jesus is Mariana's twin brother and an adopted son of Stef and Lena. He is athletic, protective, outgoing, and loyal. He struggles with school, relationships, and personal challenges as he grows up.

Jude is Callie's younger brother and Stef and Lena's adopted son. He is quiet, sensitive, thoughtful, and observant. He gradually becomes more confident and explores his identity throughout the series.

Mike is Stef's ex-husband and Brandon's biological father. He is a caring father who tries to maintain a close relationship with Brandon while navigating his complicated history with Stef. (he’s not in the main household what comes along sometimes.