Chessy is a kind, loving, and caring woman. She has been with Nick since the twins were born, and subsequently has a very close bond with Hallie, perhaps even closer than her father. She is a very observant woman, noticing the changes in behavior that Hallie displays after coming home from camp, and correctly interpreting that Meredith Blake only wants to marry Nick for his fortune.
Role in the film
Chessy first appears when Annie, disguised as Hallie, comes home from summer camp, greeting her exuberantly. She welcomes her into the house and helps her unpack, at the same time telling her about Meredith Blake and voicing her suspicions that the woman is only after Nick for his money (although she encourages Annie to find that out for herself).
The next morning, Chessy prepares a large breakfast for Annie, only to grow concerned when she doesn't seem to be hungry, following that she had very little of the chili she made the day before, Hallie's favorite. Annie reassures her, and Chessy brings up that she was talking on the phone the previous night at midnight in her bathroom (a conversation with Hallie in England). Annie fabricates a story with a clumsiness that Chessy easily sees through, but lets the issue go and tells her that her father wants to see her after she finishes eating. Chessy's suspicions grow as she only take a bite of toast before saying she's done, Sammy barks at her, and Annie has difficulty opening the glass door.
Chessy later confronts Annie after the latter voices her stress at the situation with her father and Meredith, though without giving specifics. When Chessy reveals herself to have been sitting in a nearby chair, Annie remarks that Chessy "gave her a fright." Chessy then lists the oddities that had been going on since she came home from camp, and Annie explains it away by saying that she changed a lot over the summer. Chessy uncertainly accepts the explanation, and voices her thought that she thought she was Annie, though she cuts herself off before saying the girl's name. Correctly interpreting the situation, Annie reveals her identity, and Chessy begins crying in happiness. She keeps her secret from Nick when he comes in the room a moment later, and then goes off to prepare something special for Annie. She later looks out of a window following Annie's ballistic reaction to Nick saying he planned to marry Meredith, reaffirming that she knows nothing. (At one point, when Meredith summons her with a bell, Chessy appears, saying "You rang?")
After Annie confirms Chessy's suspicions that Meredith was a gold digger, she contacts her twin for help, moving up their plans to get their parents together. While Hallie explains the truth to her mother, Chessy helps Annie set up a rendezvous at the Stafford Hotel in San Francisco, ostensibly for a good location for the wedding, keeping Nick and Meredith ignorant of the truth. Sammy's eagerness at smelling Hallie nearby leads Chessy and Annie away from Nick and Meredith. Chessy loses hold of Sammy as the dog spots Hallie in an elevator and runs eagerly to her. She then turns away as a drunk Elizabeth talks to Annie, thinking her to be Hallie, and tells her to meet her "upthairs." Chessy escorts Annie to her room, and welcomes Elizabeth when she arrives, remembering that she always liked the other woman after she gives her a warm welcome.
Shortly afterwards, Chessy meets and becomes infatuated with Martin, Elizabeth's butler, who had also been informed of the full story. They and the twins uncomfortably confide it to Elizabeth before they head down to the pool, observing the reuinion between Elizabeth and Nick from a distance. That night, Chessy acts as their server on the arranged date for the divorced couple, Martin alongside her as a sommelier, and the two of them grow more fond of each other.
When the girls coerce Elizabeth into coming home with them for a camping trip before they separate with their respective parents, Elizabeth manages to trick Meredith into going in her place. She and Chessy look on smugly as the vehicle leaves, the latter remarking that she would pay big money to see Meredith climb a mountain. She and Martin leave for a picnic at around noon, and do not return until the following evening, inadvertently spoiling a growing romantic moment between Elizabeth and Nick.
When Nick and Elizabeth reconcile and remarry, Chessy is seen on the wedding ship, and Martin proposes to her. She is last seen in the post credit photos dancing with the twins and having fun with Martin.
- In the scene where Meredith calls her with a bell, Chessy's response is "You rang?" This is similar to the Addams Family butler Lurch, who says the phrase in response whenever one of the family members calls for him by pulling a bellcord shaped like a hangman's noose, which makes a gong-like sound.