She is portrayed by Katie Iacona.
When Mercy was being released, her girlfriend Tricia was scared it meant the end of their relationship and contemplated planting drugs in Mercy's bunk to mess up her release date. Miss Claudette ultimately persuaded her not to, as it would not be an act of love ("Imaginary Enemies"). Mercy was released from prison and lost touch with Tricia.
When Tricia died, Big Boo called Mercy to inform her of Miller's death ("Tall Men with Feelings").
- Carrie "Big Boo" Black (ex-girlfriend): Mercy and Big Boo dated prior to season one.
- Tricia Miller (ex-girlfriend): Mercy and Tricia dated until Mercy's release. Tricia did not manage to contact Mercy although they promised each other they would stay in touch. Tricia later overdosed and died ("Bora Bora Bora").