They weren't supposed to make it out of infancy.
"We didn't know if they were going to survive 24 hours," Felicia Hogan says of her daughters Krista and Tatiana in a new CBC documentary. "And then 24 hours went by and they survived."
The twins have done more than survive. They celebrated their 11th birthday in October. They've learned to swim. And despite dealing with Type 1 diabetes and epilepsy, Krista and Tatiana go to school in Vernon, B.C. for a few hours every day.
"For them to actually be here for 10 years is just a blessing," Hogan told HuffPost Canada in an interview. "It just felt so good to see them get to this milestone."
The documentary "Inseparable: Ten Years Joined At The Head," follows the Hogan family for a year leading up to the girls' 10th birthday party. Along with the twins, Hogan and her husband Brendan are raising three other children: 15-year-old Rosa, 13-year-old Christopher, and 9-year-old Shaylee.
Krista and Tatiana are ordinary girls with extraordinary abilities. As craniopagus twins — conjoined twins attached at the head — they are one in 2.5 million. They share a "thalamic bridge" that connects their brains, allowing them to see through each other's eyes, taste what each other eats, and even know each other's thoughts without speaking.
"The abilities they have that no one else could imagine having are just incredible," Hogan said. They play together, and without saying a word, get up when one decides she wants to do something else.
They're just little people that are here living their lives like the rest of us.Felicia Hogan
Krista and Tatiana's doctor, pediatric neurologist Dr. Juliette Hukin, has tracked their development since they were two. "They're the only twins that I'm aware of who are alive and remain conjoined with this shared connectivity," Hukin said in a press release.
Now that the girls are old enough to describe their experiences, doctors can better understand their connection, said the documentary's director and executive producer Judith Pyke.
"It was cool to hear from them about how they can see through each others' eyes or move each others' limbs," Pyke said in an email. "But just as striking is they get along incredibly well."
Despite their unfathomable connection, they're very typical siblings, Hogan said. They have "off moments" when they argue and scream at each other.
"They're definitely different" in personality, she pointed out.
Krista is the family's jokester. She loves playing pranks and making people laugh. She is also the bigger twin and tends to take charge, Hogan explained.
Tatiana, on the other hand, is a "little lovebug." She loves cuddling animals and wants to hug everyone who comes by the house.
The girls love running around outside and going camping — and like all kids these days, play video games and watch funny videos on their iPad.
"They're just little people that are here living their lives like the rest of us," Hogan said. "That's how we see them and that's how their siblings see them."
"Inseparable: Ten Years Joined At The Head" premiers on CBC this Sunday, Nov. 5 at 9 p.m. ET.
Hogan said this will be the last documentary about the twins for now. Now that they're 11, she said, they can decide for themselves how much to share with the world.
Previously On HuffPost: