The mystery was solved. In a way, Keegan was her own twin.
"In her blood, she was one person, but in other tissues, she had evidence of being a fusion of two individuals," Uhl said.
It's a rare condition called chimerism, with only 30 documented cases worldwide. In Greek mythology, "chimera" means a monster: part goat, part lion, part snake.
In human biology, a chimera is an organism with at least two genetically distinct types of cells -- or, in other words, someone meant to be a twin. But while in the mother's womb, two fertilized eggs fuse, becoming one fetus that carries two distinct genetic codes -- two separate strands of DNA.
The twin is invisible, but for chimeras the twin lives microscopically inside the body as DNA.
When Uhl told Keegan she was her own twin, Keegan said she was shocked. "You wouldn't imagine that that could even be possible."
But what did this new discovery mean for Lydia Fairchild, the woman living across the country who'd been fighting to keep her children?
The state was still so suspicious of Fairchild that when she gave birth to another child, a court officer stood in the delivery room to witness an immediate DNA test.
"They took DNA from the baby and myself right then and there, after birth, and it came back that there is no way possible that baby is mine," Fairchild said.
Even though they'd witnessed the birth, officials believed she was acting as a surrogate, possibly bearing a child for money.
Fairchild's attorney was determined to solve the mystery. That's when he came across Keegan's chimera story in the New England Journal of Medicine.
"I asked the judge to postpone the case until these tests could be done," Tindell said.
After the tests were done, there was proof that Fairchild was her own twin as well. The judge finally believed Fairchild was the biological mother of her children and dismissed the case.
"I probably wouldn't have my kids today if they didn't discover her situation. They wouldn't have known to even consider me as a chimera," Fairchild said.
If not for Keegan, Fairchild said she might have lost her family forever.