Lakshmi's twin stopped developing in their mother's womb. As the surviving fetus, Lakshmi absorbed the limbs, kidneys and other body parts of the undeveloped fetus. Her rare condition is called isciopagus.
The complications for Lakshmi's surgery are myriad: the two spines are merged, she has four kidneys, entangled nerves, two stomach cavities and two chest cavities. She cannot stand up or walk.
A team of neurosurgeons has separated the fused spines, and will next try to remove the extra limbs, then the rest of her "parasitic twin," said Dr. Sharan Patil, the orthopedic surgeon heading the operation. The surgery began early Tuesday.
"The child has been responding very well," Patil told reporters outside Sparsh Hospital in the southern city of Bangalore where Lakshmi is undergoing surgery, several hours into the surgery.
Patil warned that the surgeries would "take many, many hours on a continuous basis" up to 40 hours and involved 30 surgeons.
Before the operation began, he said there was a 20-25 percent chance Lakshmi would die during the operation.
"It's a big team effort of a lot of skilled surgeons who will be putting their heart and soul into solving the problem of Lakshmi," Patil said.
It wasn't immediately clear if doctors expected her to ever be able to stand or walk before the surgery, her limbs were severely atrophied.
Lakshmi is named for the four-armed Hindu goddess of wealth, and some in her poor village in the north Indian state of Bihar highly revere the little girl, her father, Shambhu, said.
"Everybody considers her a goddess at our village," said Shambhu, who goes by one name.
He said the family feared people would try to make money from her and, after an unsuccessful attempt by a circus to buy her, they had kept her in hiding.
Dr Patil Mamatha said the hospital's foundation was paying for the surgeries because her family could not afford the medical bills.
Lakshmi is popular among the medical staff and other patients, Mamatha added.
"She's a very cute girl," she said. "She's very playful and gets along well with others."