In 2017, Hanna was told she had six months to live.
"When I got the news, I got straight on the phone to Social Services. I just needed to know my children were OK," she says.
At that point, 11 years after her children had been taken from her, Hanna had had no news of them for seven years.
As a teenage mum who'd been in and out of care and had no support network to speak of, Social Services had deemed Hanna unable to care for her children.
Hanna describes the moment she watched her 14-month-old twins driven away to their new family as "the worst day of my life". She was 16, and had spent more than a year fighting to keep them, while living in a mother and baby foster placement.
"Mum used to beat me up until I was black and blue. I think they worried that history would repeat itself," she says.
Like most birth parents in the UK, Hanna was granted "letterbox contact" when her children were adopted - an agreement meaning she could exchange letters with her children and their adopters until the children reached 18.
In her case, the judge extended the typical once or twice a year letterbox to three times a year, specifying that Hanna should also be allowed to send her children birthday and Christmas cards as well as receive photos from the adopters.
But making arrangements is one thing - maintaining them is something else altogether.
About a year after her children were gone, true to the "letterbox contact agreement", Hanna received the first of many letters. But rather than uplifting her, it pushed her into a "deeper depression".
"The letter was written as if it had been written by my children, saying 'Mummy and Daddy did this with us, we did that.' But my children were only two, it was clear they hadn't written it."
As time progressed, letters continued to arrive. But Hanna increasingly left them unread. "It was as if they were following a particular template - 'We went on holiday, we went horse-riding.' None of them told me anything I wanted to know, like how my children were developing or what their interests were," she says.
"In the end I'd take the photos out and not read the letters as it was too painful."