Nine-year-old orphan Amanda Lemmon is being sought after by Harry and Fanny Butkis, a reclusive and secretive couple known to "collect" kids via adoption. However, she wants her likeable and warm-hearted social worker, Diane Barrows, to adopt her instead. Unfortunately for Amanda, authorities will not let Diane adopt Amanda due to the former's low salary, unmarried status, and social worker position, despite her interest in doing so. While at a
summer camp, Amanda meets a rich nine-year-old girl named Alyssa Callaway who looks just like her. Alyssa has just come home from
Windsor Academy, only to find that her wealthy widowed father, Roger, who is the owner of the camp and president of Callaway Cellular, is about to marry an overbearing, self-centered, gold-digging socialite named Clarice Kensington the following month. Amanda and Alyssa soon become acquainted, each longing for the other's life and decide to switch places. While Amanda adapts to Alyssa's wealthy lifestyle and Alyssa experiences summer camp, they get to know the other's parental figure and realize that Roger and Diane would be perfect for each other. Desperate to set them up, the girls arrange many meetings between them, hoping that they will fall in love. Roger and Diane seem to hit it off upon meeting, as she is pleasantly surprised by how, in spite of his wealth, he is kind and humble. Roger, with Diane's help, works up the courage to revisit the camp, which he has not done since his wife Cathy (Alyssa's mother) died due to painful memories of her untimely death when Alyssa was born. After seeing Roger and Diane laughing and swimming together in the lake one afternoon, Clarice manipulates Roger into moving the wedding from the following month to the next day, and Amanda, while posing as Alyssa, discovers that Clarice plans to send Alyssa to
boarding school in
Tibet afterwards. Alyssa then ends up being adopted by the Butkises without Diane's knowledge while posing as Amanda; the Butkises name her Betty. A few hours before the wedding, Amanda tells the Callaways' butler, Vincenzo, that she is not Alyssa. He visits Diane at the orphanage and informs her about the switch. Diane then goes to the Butkis residence to pick up the real Alyssa and get her to the wedding. However, nobody is there and a neighbor tells Diane that the only reason the Butkises adopted so many kids was to work them in their
salvage yard as slaves. Enraged, Diane takes Roger's company helicopter to the salvage yard to reclaim Alyssa (disguised as Amanda) and threatens to report the Butkises to social services, giving their seven other adopted children hope for salvation. Vincenzo and Amanda try their best to stall the wedding. As Roger hesitates to say, "I do", he remembers the good times he had with Diane and realizes that he has fallen in love with her and cannot marry Clarice. Suddenly, Diane bursts into the church with Alyssa behind her. At that moment, Roger confesses his love for Diane to Clarice, who furiously slaps him. Clarice tries to do the same to "Alyssa", blaming her for ruining the wedding, but is stopped by Vincenzo. As Clarice storms down the aisle, the real Alyssa steps out from behind Diane. Clarice declares that there is a "conspiracy", thinking that there are two Alyssas. Clarice attempts to hit the real Alyssa but Diane steps forward in time, barking "Back off, Barbie" at Clarice, before calmly informing Clarice that she has something in her teeth. Humiliated, Clarice moves to storm out of the church again, but Alyssa deliberately steps on her wedding gown, causing it to rip off. This exposes Clarice's undergarments in front of all the wedding guests, even those with cameras, causing Clarice to desperately call for her father (who just laughs) and run away, trying to hide her undergarments from the flashing cameras. An incredulous Roger learns that Alyssa has been with Diane while he had Amanda all this time, and they realize that the girls had orchestrated their meetups all along, about which they are extremely smug. After some encouragement from the girls, Roger and Diane share their first kiss and the four of them board a horse-drawn carriage, driven by Vincenzo, to take a ride through
Central Park. ==Cast==