There have been at least two recos for Pratchett and/or Discworld, and I have to third it. I read my first Pratchett around the same time I was reading HhGtG, just barely in high school, and didn't know about the rest of his work. Years later I got into it and devoured all forty three or however many books.
Others have mentioned Terry Pratchett, but I'd like to add his Tiffany Aching books were written specifically for a younger audience. So, they would be a great place to start.
My daughter is a little younger but has been enjoying The Kicks book series. If your daughter is into soccer/football she might like them too. They are written by Alex Morgan.
Maybe a bit left field, but I'd suggest something by the Brontë sisters (Wuthering Heights, Jane Eyre) or Jane Austen. Never too early to start on the classics and those should be reasonably approachable.
As plenty of others have said, Terry Pratchett for sure. The Tiffany Aching books were written for younger readers but are not at all “childish”. You could start anywhere but I would suggest The Wee Free Men first.
As others have suggested, the Discworld series for sure. Also, Jane Eyre by Charlotte Bronte. I read it when I was 10 and fell absolutely in love with it.
The Cytoverse series by Brandon Sanderson, starting with Skyward. Age appropriate, female protagonist, sci-fi.
Also, I see someone else in this thread recommended Blood Meridian, and I feel like I should say that's not a good recommendation for that age group. It's a good book, and Cormac McCarthy is a great writer, don't get me wrong, but it is also bleak, super violent, and dense.
There is an absolutely fantastic series called The Gilded Ones by Namina Forna that she would probably love; I saw it on a list of books that are a way better alternative to Harry Potter, read it, and haven’t stopped recommending it to others.
The Wayfarers series by Becky Chambers is a great warm-and-cozy kind of sci-fi, also well worth the read.
The House In The Cerulean Sea by T. J. Klune is a beautiful read about a group home of misfit children
The Deep by Rivers Solomon, an interesting twist on a mermaid story
The Psychology of Time Travel by Kate Mascarenhas is a really cool story that mixes up a murder mystery with time traveling
The Maise Dobbs series by Jacqueline Winspear; the series starts in the 1910s and follows a young girl who grows up to become a private investigator in the 20s and 30s
Almost anything by Neil Gaiman, but particularly The Graveyard and Coraline are awesome, creepy reads, if she’s looking for something like that
Steelheart by Brandon Sanderson is good, probably on the more grisly side for a tween (probably in the same vein as Hunger Games?). Elantris (also by Sanderson) is a great read too.
For fantasy, "The Belgariad" and "The Mallorean" sagas by David Eddings were amongst my favourites when I was that age, and the "Magician" books by Raymond E. Feist. My ex-wife introduced me to the work of Robin Hobb and Cecilia Dart-Thornton, both of whom are excellent. "Mistborn" by Brandon Sanderson will probably be an all-time favourite, it is for me and my partner! I also loved the Myth books by Robert Aspirin, for a lighter read, and I'd be remiss if I didn't mention basically anything by Lawrence Watt-Evans. His Ethshar books hold a special place in my heart.
I'm so happy for you that she likes science fiction too! Iain M. Banks' "Culture" series is great, and of course The Dragonriders Of Pern by Anne McAffrey is a classic. Lawrence Watt-Evans again, he wrote "The Worlds of Shadow" trilogy which is a neat blend of science fiction and fantasy. There's also The Dark Tower by Stephen King which I read around 11 or 12. It's great, but maybe a bit dark which I've otherwise tried to stay away from in these recommendations.
Speaking of dark, for when you feel she's ready: Joe Abercrombie's "First Law" series is some of my favourite dark fantasy I've ever read, but man is it grisly.
Edit: How did I forget Pratchett?!? And by extension, Neil Gaiman. "Good Omens" is a brilliant read, and the series adaptation is excellent too. There are just too many good authors to recommend in threads like this, which I guess is a good problem to have!