Role in the film
Kirby was a waitress at Winston and James's favorite restaurant. James met and fell in love with her. Kirby persuaded him to adopt a healthier lifestyle, which did not sit well with Winston.
She eventually broke up with James which sent the latter into a deep depression and reverting back to eating junk food, which initially delighted Winston. However, Winston could not take his master's depression, (which consisted of holding a piece of parsley and staring at it) and came to the restaurant with the parsley to get her back. James followed him to the restaurant and Kirby reconciled with him and eventually married him, having a son and a daughter.