In 2002 the pair made international headlines when surgeons at Mattel Children’s Hospital at UCLA Medical Center separated them, however while Josie is a fun-loving, dancing and singing fifth grader, Teresa is unable to move or speak.
The 11-year-old told People magazine: 'I always dream about my sister, and in my dreams we're playing together. I share my friends with her and I know she shares my joys.'
Birthday fun: Ten years after their separation surgery, Teresa (left) and Josie (right) celebrate turning 11 together
Born in a Guatemalan village joined at the head, the girls were not expected to live longer than one year.
Sisterly love: Josie told People magazine: 'I like making her laugh by blowing in her face or holding her arm until she smiles'
While the surgery was successful, Teresa contracted deadly meningitis after the twins returned home in Guatemala. She spent five months in 2003 in and out of a coma, which left her disabled and in need of round-the-clock medical care.
Josie fared better but was suffering from grand mal seizures and came down with hydrocephalus, fluid build up on the brain.
Their medical needs, primarily covered by insurance after they were flown by a private jet back to the U.S., convinced the twins' parents that in order to ensure their survival, they needed to remain with their American host families.
Jenny Hull, 51, adopted Josie, while Werner, 51 and Florie Cajas, 50 adopted Teresa.
'I light a candle for my sister every Sunday,' said Josie, who sees her twin several times a week for shared meals, physical therapy and sisterly hang-out time.
Despite living 50 miles apart, she added: 'My sister and I have been very blessed.'
Josie, who has been practicing synchronized swimming for three years, loves singing, history and computers, and walks with a cane for support, said: 'I want to walk without a cane, but my closer goal is walking while only holding my mom's hand.'
Josie's doctor, Mark Urata, who will close the remaining part of her skull, currently covered by a skin graft, later this year, said: 'She has the capacity to achieve anything.'
The twins' biological parents visit twice a year, revealing: 'We're able to sleep at night knowing they are loved and cared for.'
Forever bound: In 2002 thetwins made international headlines when surgeons at Mattel Children¿s Hospital at UCLA Medical Center separated them, however Teresa is unable to move or speak
Growing up: Born in a Guatemalan village joined at the head, the girls were not expected to live longer than one year, however they have just celebrated their 11th birthday
Small smiles: The nonprofit organisation, Healing the Children, of which actor Mel Gibson (pictured) is a beneficiary, flew the twins and their birth parents to Los Angeles where they underwent a 23-hour separation surgery in 2002
Natural talent: Josie has been practicing synchronized swimming for three years, and loves singing, history and computers
'Their heads come together. Teresa just lights up when they do that. They have a deep love. It is beautiful'.
She added: 'We all have a shared love for the twins, and because of them our families will be connected for the rest of our lives.'