The two girls, aptly named Faith and Hope, arrived last Thursday after a short labour in Sydney, Australia.
Faith and Hope are the result of an extremely rare condition known as disrosopus, where a baby is born with two faces.
Fewer than 40 human disrosopus cases are known to have been born. Even fewer survived beyond birth.
The couple said even though the baby only had one body, they still referred to them as their beautiful baby twins.
"I think they're beautiful and Simon thinks they're beautiful so really
that's all that matters," Ms Young said in an interview with an
Australian TV show, 'A Current Affair'.The parents, who already had seven children together prior to the girls' arrival, discovered the abnormality during pregnancy but decided against an abortion.
"I would say, if I only get two days with the baby, I only get two days with the baby, at least I have some time with it," Ms Young said.
But the couple are confident they will spend far more time with their newborn girls than that.
"A little luck, a little bit of faith, a bit of hope, hopefully we'll come out the other side, as long as they're fighters and they keep fighting, everything will be okay," Mr Young said.
Renee and Simon discovered during their 19-week ultrasound that their
unborn babies were both girls and that they would be born with a rare
condition called diprosopus.The condition means that the girls have separate brains but identical faces on one skull and share the same body and organs.
"Even though there is only one body, we call them our twins," explains Simon. "To us, they are our girls and we love them."
There are a number of details about how the babies will now function that remain unclear, but doctors have been monitoring Renee throughout her pregnancy and will continue to watch her and her miracle daughters closely in the first crucial weeks of their lives.
The girls are conjoined in such a rare way that there has only ever been 35 similar cases recorded in history, and only 16 in the last 150 years. Sadly, none of those babies have survived. According to reports, the last known case was in 2008 in a poor Indian village.
Renee and Simon say they are prepared for the challenges that lie ahead.
"We have no idea how long they will be in hospital, we just want to bring them home, happy and healthy to make our family a little bit bigger and a bit more chaotic," Simon said.
[-Woman's Day]
