The extraordinary efforts of the girls' adoptive parents Jenny Hull, 41, (who adopted Josie) and Werner Cajas, 51, and Florie Cajas, 50, (who adopted Teresa) helped create the joy the girls displayed while celebrating their 11th birthday in matching pink frilly dresses and sparkly tiaras on July 14.
While Josie belted out a karaoke version of Lady Gaga's "Born This Way" and led a parade of pals across the lawn in her motorized walker, Teresa watched from a wheelchair, unable to move or speak. Still, she cracked a smile – and that's enough for her twin.
"You can tell she's happy," Josie says. "My sister and I have been blessed. We're lucky."
Early DaysBorn joined at the head in a Guatemalan village to Wenceslao, 31, and Leticia Quiej-Alvarez, 32, the girls were not expected to live more than a year. But with help from the nonprofit Healing the Children, the family was flown by private jet to Los Angeles. There the twins underwent a grueling 23-hour separation surgery on Aug. 5, 2002, at Mattel Children's Hospital UCLA, which made international headlines.
The joy at that successful operation was followed by a tougher reality. Back in Guatemala, Teresa contracted a brain infection that left her in need of round-the-clock care. Josie battled seizures and other medical problems. To ensure their daughters' survival, the Quiej-Alvarezes made the gut-wrenching decision to allow the girls to be adopted. (The birth parents visit twice a year.)
A New LifeVirtually overnight, Jenny traded a carefree life of beach volleyball and world travel as a personal assistant to become a single mother of a special-needs child. Every morning before sunrise, Jenny lifts Josie, who cannot walk unaided, out of bed, and loads her 100-pound motorized walker into the car before driving her to school. They also make a two-hour roundtrip drive three times a week for intensive physical therapy to help fulfill Josie's dream of walking without canes.
"When the twins were just babies, I had complete admiration for their fighting spirit," Jenny tells PEOPLE. "It became my calling to help them continue to live. It's been a blessing and complete gift to be a part of their lives."
As for the Cajases, this was their way of giving back to Healing the Children, which in 1994 had arranged life-saving heart surgery in L.A. for their youngest child, Kevin, from their native Guatemala. After emigrating to the U.S., the family was asked to temporarily care for Teresa.
"We immediately said yes," says Werner, a physician-turned-pastor. "She had spent so much time in the hospital, we wanted to provide her an environment of love." His wife Florie, who tends to Teresa's feeding tube and array of medications daily, says, "Taking care of Teresa has taught me patience. She has expanded our hearts. I love her as my own daughter."
Cris Embleton, the former director of Healing the Children's L.A. chapter says Josie and Teresa – who today are treated by a team of doctors at Children's Hospital Los Angeles – bring out the best in people. "Because of them, hundreds of people have stepped forward over the years to donate time and money to needy children around the world," she says. (The sisters' medical costs are covered by private donors.)
David Butow / Redux
"We made a vow never to keep them apart," says Jenny, who along with Josie calls the girls' biological parents in Guatemala every Sunday.
Werner agrees, saying, "We all have a shared love for the twins, and because of them, our families will be connected for the rest of our lives."
Adds Embleton, "The twins now have three moms and two dads. Theirs may look different from yours or mine, but there's no question: They are one big family."
Know a hero? Send suggestions to firstname.lastname@example.org. For more inspiring stories, read the latest issue of PEOPLE magazine