Danielle Brooks is Annie Walker's sister. She is married, has two daughters and lets Annie live in her guest house. She initially doesn't know about Annie's job, which creates a lot of tension between them, like when Annie isn't sure she can sign a will to be the guardian of Danielle's children, or when Annie loses a three-hundred-dollar carry on during a mission. Danielle fights with her sister occasionally, but they always make up, and seem to really care for each other.
Danielle is a responsible mom and balances her husband's high-powered career. She loves her family, which is probably why she's always trying to get Annie to follow suit. She sets Annie up on countless dates (which Annie hates), and believes that Annie needs to move on from her whirlwind Sri Lankan romance with Ben Mercer.
Annie eventually chose to read Danielle in, following the death of one of her co-workers. Danielle, hurt and upset that Annie lied, announces that she is leaving. Danielle has now moved to California and been dropped to recurring status. It is unclear when or if we will see her again.