In 2012, Angela Formosa wasn't sure she would see her daughters survive their infancy. So it's incredibly special that Rosie and Ruby, both now 4, are ready to start their first day of kindergarten in September.
The twins were born conjoined at 34 weeks and delivered through C-section at the University College Hospital in London. They were joined at the abdomen and shared part of their intestine and had only a 20 percent chance of survival.
Rosie and Ruby then had emergency surgery just a few hours after being born because of an intestinal blockage.
According to the University of Maryland Medical Center, cases of conjoined twins are extremely rare. It occurs once in every 200,000 live births, and only 35 percent of conjoined twins are expected to survive the first day. The decision to separate conjoined twins can be a difficult one when the chances of surviving surgical separation can be even lower than pregnancy or birth. In 2014, first-time parents in Pennsylvania decided to keep their twin boys together because they shared a liver and a heart.
Formosa says the heartbreaking surgery and experience now seems so far away.
"The time has just flown by, I can't believe how fast it has gone," the mom told BBC. "Four years ago, it wasn't in my mind that this would ever happen."
Now, every milestone is a huge celebration and one to remember for the family.