What a strange question?
If they are interested in fantasy movies give them a fantasy book. If they're interested in mystery, the same. If they're interested in Dinosaurs, the same. How is this some great challenge? The things you like to read about are the same things you already like... Are you implying you know nothing about your daughter?
Of course it is hard to do - at least, harder to do than saying "I have a 5 year old, and this book says it is for 5 year olds, so I will have them read it".
I'm not saying they are not worthy of consumption or anything like that, but A: I doubt very many teachers would accept a "book report" written about a graphic novel and B: consuming graphic novels, by their nature, is not purely reading. Your brain/imagination has far less work to do, as you don't have to mentally picture the scenes/people/actions, they are right there for you to look at.
These are... not books.
you don't have to mentally picture the scenes/people/actions
I remember when I was in middle school, my English teacher had a box in the corner of comic book adaptations of about a dozen "classic" stories. Several were stories by Poe, and similar 1800s-era classics. (Dracula, Sherlock Holmes, etc.) I devoured them (despite loving reading "regular" books too). I've forgotten most of the plots, but remember having enjoyed reading them. Some of them, I've never read the originals, but for others I had already read (or subsequently read) the more-detailed originals. (Anything Sherlock Holmes, at the time, was something I enjoyed.)
Reading these stories as a manga makes you lose out on a lot of details, but probably makes it a lot easier to digest some things. Pride and Prejudice, for example, has pages of details of peoples' social lives, and the complex interactions of several younger and older women, along with descriptions of gardens and houses, and I know that I definitely had trouble keeping track of who all the ancillary characters were. Having visual representations of these characters might make it easier to track that. You lose out on the richness of Austen's prose, but you keep the core character developments, relationships, and emotional interactions that form the basis of the stories.
I'd enjoyed The Malazan Book of the Fallen more if I had this edition: https://subterraneanpress.com/erikson-gotm/
I'd posit that anyone whose imagination conjures up mental pictures from a purely written book would be incapable of not doing so with a graphic novel. One's brain could have less to do, true... yet it doesn't choose the easy path. In my personal experience, the scenes of a good story grow and become more detailed in my imagination, regardless of whether they are depicted in prose or picture.
One thing I love about written language is that can be used in so many ways; the vast majority of reading isn't 'purely' reading for me, but associated with other activities - encyclopaedias are reading interspersed with skimming, possibly in order to inform another task such as writing, graphic novels are the appreciation of visual art in a narrative form supported by text, and then there's the entirely practical way in which being able to read "wet paint" helps me from getting myself into a sticky situation.
If you haven't yet, push out beyond fiction. In my experience, libraries have a really divergent collection of large, illustrated volumes.
When I was 5-10 I read comic strip books - but also encyclopedias. Specifically World Book; Britannica was too dry.
note: I've no complaint with graphic novels. Sons 1, 2 & 5 were big into them. One is writing fiction. Two was into physics and anime, is now into psychology and early Japanese film making. Five performs+crafts his own music videos.
For the the mid-teens, Mistborn series.
We've taken her to the library since she was a baby where we'd find new baby books to read to her. Over time, we stopped picking out books for her and let her wander the isles, picking whatever seemed interesting to her. She usually chooses a wide assortment of things from comics to YA fiction.
My son is much more interested in screens, but he still reads a lot. Whenever we restrict the screens his next default is to read.
We read a lot to both of them as infants & toddlers. We have a couple bookshelves worth of books in the house, but honestly they spend almost their whole reading time on new-to-them library books. We've hit the library checkout limit pretty much every time we go! And it's no waste - every book is returned read.
> if you have a kid who doesn't have an existing strong reading habit, how do you find books they'd be interested in?
I'd start by taking them to the library and letting them explore. Chances are they'll find something that interests them!
"Give your kids books they'd be interested in" is kind of classic meaningless advice. Like, sure, of course that's what you want to do -- except, if you have a kid who doesn't have an existing strong reading habit, how do you find books they'd be interested in? Like, that's the goal! You can't just assume the solution.
I have a nine-year-old daughter who definitely does read, but isn't a voracious reader, and I've tried a lot of different things to up the amount of time she spends reading. It's tricky. One of the things that I've found is she's more willing to invest in graphic novels than prose novels, but I don't feel like at this point graphic novels deepen her literacy.