They thought she was lying about giving birth to her three children because the DNA didn't match. Then, they found she's 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."