Credit: Getty Images (2)

The mother of a young cancer patient has shared a touching letter to J.K. Rowling, thanking her for the Harry Potter books and how they helped her daughter get through treatment.

At this year’s Letters Live, a U.K. event in which performers like Jude Law, Gillian Anderson, and Benedict Cumberbatch read letters aloud, actress Ellie Bamber read a letter from Chrissy Hart about what Hart and her daughter learned from the Harry Potter series.

“I want to share with you what you taught my daughter, who was recently diagnosed with cancer,” Hart wrote. “When I read her your stories, she didn’t take to the clear distinction between good and evil, but instead loved the grey characters. You taught her that for every chemo she has to go through, there will be the opportunity to fly across a lake on a hippogriff. For every time her heart seizes with fear of pain, there will be me chasing it away with a patronus charm. Your words built a castle for her to move into when the prognosis got worse.”

The event’s organizers told BBC News that Hart’s daughter died earlier this week.

Star Wars: The Force Awakens actress Daisy Ridley later shared Hart’s letter on Instagram, writing, “One of the most beautiful letters I’ve ever read. From a mother to JK Rowling, about the impact Harry Potter had on her daughter, who was diagnosed with cancer. The power of words is undeniable. Full link here, it may make you cry. Just gorgeous.”

Read Hart’s full letter at BBC News.