Role in the film
Meredith is first seen when the two protagonists, Hallie and Annie, are switching places. She is a publicist from San Francisco who Nick hired to do some publicity for his vineyard and they wind up dating and eventually get engaged. She has an assistant named Richard, where she secretly plots to send "Hallie" (actually Annie) off to a boarding school in Timbuktu. She reveals to "Hallie" that whether the latter likes it or not, Meredith is going to marry Nick, much to her disappointment, both because the twins plan on getting their real parents remarried and because Meredith is 15 years older than Annie (she is 26). She also reveals to Annie her true plot that she is only marrying Nick for his money.
At the Stafford Hotel Meredith introduces Nick, Annie, Chessy, and Sammy to her parents Jesse and Vicki Blake. Another time, when Nick and Elizabeth are together again at the swimming pool, Meredith is astonished to meet Elizabeth. She is also shocked to find out that Hallie and Annie are two people (twins) when she sees one on each side.
Annie's biological mother, Elizabeth, talks Nick into taking Meredith camping instead of her. Because Meredith isn't used to the altitude of the mountains, the twins play a trick on her by putting a lizard on her water bottle and putting rocks in her backpack. She is handed the bottle and freaks out at the sight of the lizard. Then, as she threatens to make the girls' lives miserable starting the day she gets married if they pull another trick on her, one of them calls her "Cruella". Meanwhile, one of them has put a lizard on her head, and she freaks out when she finds it, and it gets in her mouth, causing her to choke.
That night, she reveals that she doesn't eat trout. After she gets into her tent to sleep, Hallie and Annie pull her mattress out of the tent and push it into the lake. The next morning, as she wakes up, she finds a bird perched on her and wakes up screaming. She also screams when she finds out her mattress is on the water, and falls off it. Soaking wet, she kicks a pot and angrily tells Nick that the day they get married is the day they ship "those brats" off to Switzerland. She then demands Nick choose between her and the twins, and he chooses the twins. She angrily freaks out in a tantrum and calls off the engagement. It is unknown what happens to her next but it is likely that either her parents or Richard came and picked her up.