Caitlin D'Arcy, the niece of one of Lockhart/Gardner's equity partners, David Lee, is lawyer who joins the firm in the third season.
She is first seen in "Marthas and Caitlins" when she interviews for a position as a first year associate at the firm. Alicia is asked to interview her and her opponent Martha. Initially, Alicia decides in picking Martha before David Lee informs her that Caitlin is his niece. Alicia still tries to choose Martha, but is told that the firm has taken a vote and decided to hire Caitlin. Gh
In "Affairs of State" Caitlin works with Alicia and the firm in a defense lawsuit for a young Taiwanese man, who may or may not have diplomatic immunity. She does well on her first day.
In "Parenting Made Easy" Alicia coaches new associate Caitlin D'arcy in her first court-like appearance, an arbitration hearing. Opposing counsel is Martha Reed who Alicia had hoped to hire but was forced to hire Caitlin instead.
Caitlin leaves the firm in "Long Way Home" when she find out she is pregnant. She intends to get married and raise her baby. Although Alicia and Diane both offer that she juggle both work and family, she chooses to leave anyway.