Eleanor Walsh and Jillian McNulty were the closest of friends. They were the same age and they shared a wicked sense of humour. They were so devoted to one another, they were like sisters, and Jillian was utterly devastated when six months ago, Eleanor died at the age of just 37.
But in fact, they had never met.
Eleanor suffered from cystic fibrosis, as does Jillian, and thanks to both women's compromised immune system, doctors banned them from meeting in person.
Instead, they exchanged thousands – 35,000, by Jillian's reckoning – of emails and Facebook messages, sent from their hospital beds in St Vincent's in Dublin.
Separated by just a few walls, they'd joke about the hospital food, and support one another if either was feeling low.
For both Eleanor and Jillian, isolated by illness from the outside world, those emails, texts and phone calls were a lifeline.
"We couldn't meet up and socialise, but that didn't matter," says Jillian. "It's hard for healthy people to understand how people who've never met can be that close. But she was lovely. She was just the kindest person you could ever meet.
"She never had a bad thing to say about anyone. She was so kind that she actually wrote books for kids to help them understand cystic fibrosis better, which she won an award for.
"It's fine for adults – we can accept that we have the condition – but kids have a difficult time understanding why doctors are constantly sticking needles in them. So Eleanor wanted to do something for them."
Cystic fibrosis (CF) is an inherited chronic disease that primarily affects the lungs and digestive system. In Ireland, about 1,200 children and adults are living with the condition.
According to Cystic Fibrosis Ireland, the impact of CF can vary. While some people with CF die in their teens, others can live into their fifties.
Sadly, Eleanor was not so lucky. Jillian was just a few rooms away in St Vincent's when she died on December 3, 2012. "A few days before Eleanor died, we spoke on the phone for about 20 minutes," Jillian recalls. "She said, 'I am not good, Jillian'. I just said, 'Look, chick, you'll be grand, think positive'. But she said, 'No, it's not good'.
"I knew she was going to die, but I was still hoping for a miraculous recovery."
Poignantly, it wasn't the first time Jillian had watched a close friend die. "I've had plenty of friends who've been fine one day, and gone a week later," she says. "For that reason, a lot of people say you shouldn't be friends with other CF people, as it's too hard. But while we're not all the same, we understand what the other person is going through."
Romantic relationships can be hard, too, and Jillian says she has struggled to find a partner who can take her illness on board.
"Men can get scared with CF," she says. "They don't want to know about it. They can't cope with you being sick or in hospital. People like a stress-free life, and being with someone with CF is a big commitment."
In the circumstances, the relationship between Jillian and Eleanor was all the more poignant.