She is the matriarch and eldest member of the wealthy Braithwaite family, the rivals of the Gray family. At some point before 1899, Catherine Braithwaite began selling moonshine to the Lemoyne Raiders through an illegitimate side business. She also became acquainted with Angelo Bronte.

Catherine is first seen at the Braithwaite manor when Hosea and Arthur arrive to sell her back the liquor the Van der Linde gang previously stole from her. Catherine instead hires them to give out the liquor for free at the bar in Rhodes, for some "promotional advertising". While distributing the liquor in town, Hosea and Arthur are ambushed by the Lemoyne Raiders. Whether or not this was Catherine's plan is unclear.

You then yourself from Dutch Van De Linde’s gang, were sent to negotiate with Catherine Braithwaite, who was standing outside of the entrance to her mansion.

”Yet another of your Hosea’s men… which one are you, hm? I won’t let ya’ in til’ ya give me your name.”