Emma Donoghue has lived in Canada for nearly 20 years, but she retains the lilting accent, verbal gusto, and ready charm of the inhabitants of her native Dublin. Chatting in the book-lined study of her home in London, Ontario, Donoghue is thoughtful and engaging as she discusses her new novel, The Wonder, due from Little, Brown in September. She’s also funny, not that there are many inherent laughs in a story about an English nurse sent to rural Ireland in the 1850s to watch over an 11-year-old girl who supposedly hasn’t eaten in four months, especially since the nurse encounters less-than-savory aspects of Irish society. Rampant superstition, repressive religious orthodoxy, and a wall of denial about a case of incest form the plot. Yet Donoghue manages to find mordant humor in her explanation of the novel’s origins in the real-life cases of the Fasting Girls, young women who in previous centuries apparently survived without food for long periods of time.

“I’ve been interested in the fasting girls for at least a decade and a half,” Donoghue says. “But there was not one of the real cases that made me think: Yes, I’ll write a novel about that. Most of them are too sad, even for me—there’s only so much suffering I can put a child through in a book of mine.”

Donoghue, a mother of two, is most well-known for Room, her bestselling 2010 novel about a five-year-old boy confined in a garden shed by a man who kidnapped and continues to sexually abuse the boy’s mother. Donoghue opted in The Wonder for a fictional fasting girl and a tentatively happy ending, but I ask if she worries about the reception back home for her unvarnished portrait of 19th-century Ireland.

“Of course I had those moments,” Donoghue says. “But my countrymen and countrywomen have themselves for the last 20 years been going through a major analysis of their own culture, their own history, their own traditions. The fiercest condemnation of the flaws in the Catholic Church has come from Ireland, and I feel like I’m part of that movement. I was delighted to set another novel in Ireland, actually; I felt a little sheepish that for a long time all the stories I’ve gone for have been set in England or America.”

The Wonder’s hopeful conclusion is grounded in the tender relationship that grows between 11-year-old Anna and Lib, the nurse sent to observe the fasting girl who becomes her protector and advocate. It’s Donoghue’s third novel, after Room and Frog Music, to place its emotional center in the bond between an adult and a child. “When our first kid was born 12 years ago, I had no idea that I would start writing about children in this obsessive way,” Donoghue says. “My kids said to me once, ‘What did you write about before us?’—and briefly, I couldn’t remember. I’ve got a kids’ book coming out next year, too, so they feel they’re at the heart of my creative enterprise.”

The Lotterys Plus One, to be published in the U.S. by Scholastic this April, portrays a family with two sets of same-sex parents. This is hardly a startling subject for Donoghue, who met her wife at university and made her first literary mark in the ’90s with Stir-Fry and Hood, two novels about lesbian life in Dublin. But it’s been nearly a decade since she directly explored that topic in her adult fiction. “I think lesbianism is just one of my themes,” she says. “It seems to come up in my work when it wants to. I certainly haven’t put it behind me. I think in the past 10 years my thoughts have tended to hinge on parents and children. To be honest, whenever one of my books has a lesbian plot, I know it’s probably going to sell less well than the others, though I don’t care. Room was my one big bestseller; I don’t feel I have to have one every time. Broadly speaking, being a lesbian has forced this middle-class girl from Dublin to empathize deeply. For example, I write a lot about freaks, I write a lot about slaves, and I’m interested in relations between the powerless and the powerful; I think all that comes in a ripple effect from my being a lesbian, but it doesn’t mean every story line is going to be lesbian.”

Before Room, Donoghue was best known for her historical fiction, beginning with Slammerkin in 2000 (about a prostitute in Hogarth’s London). Like Room, which was inspired by several real-life cases of abduction and long-term imprisonment, these novels are based on fact: Life Mask (late 18th-century London’s Beau Monde) and The Sealed Letter (about a Victorian England divorce case) even take actual historical figures (complete with their real names) as characters, though they are always reimagined in vivid fictional terms.

“Putting it positively, I would say that I have a very academic background,” Donoghue says. “I did a university degree and then a Ph.D., but I never got an academic job because by then I had sold a few novels. I’m an academic gone wrong, and that means my historian’s side has infected my fiction writing side; I’m hoping the result is a happy hybrid. Now, you could put it negatively and say I lack the imagination of other novelists. Sometimes I think, ‘It would be so much simpler to make it up.’ But there’s something about the slight irritant effect of a real story that gets me puzzling. I absolutely love hunting down facts, it feels like detective work, but I also love the moment when I shove the facts aside and say, ‘Now I make it fiction.’ It keeps it very varied, because your loyalties are mixed, divided between truth and fiction, and it makes you mull over what is true.”

Donoghue is currently working on a script for television and two screenplays, taking advantage of the opportunities that came her way following the well-received 2015 screen adaptation of Room, for which she wrote the script. “I got lots of offers this year, some of them wildly incongruous, like to write a wrestling movie, but some were very tempting, so I went for three of them,” she says. “Maybe I’ve taken on a little too much in the sheer excitement of it, but I really enjoyed adapting Room. I like the process; I’ve adapted stories of mine for the stage and for radio, and I’m quite pragmatic about what you have to do. It makes you really think: what are the crucial elements? How do you find a different way to make the same kind of magic happen?”

Donoghue is also working on a new novel, this one set in the present. “I think I’ll always go back and forth, but it seems as if I get one contemporary idea for every two historical. I always like to have my own projects that I’m getting on with. If you’re working solely in the film world, you’re so dependent on other people; you’re waiting for them to get back to you, or for the money to come in, or for an actor to be ready. I couldn’t stand the passivity of that.”