Edit: Solved! Dragonclaw by Kate Forsyth / The Witches of Eileanan series. Thanks heaps u/hawkgirl

Unfortunately, that's about all of the plot I remember. I never finished the book. I read it approximately 10 years ago when I was in my early teens and it didn't sink in very well.

It was a coming of age story about a girl growing up and going through a puberty analogue, where her magic powers surfaced. She had to learn how to control them quickly, and either due to this or a related event, she was taken prisoner and one thing led to another, and she was tortured, either because she was magic/a witch, or to try and get information out of her. I believe the most prominent method of torture used on her was burning with hot metal, and thumbscrews.

I believe that the main character had long red hair (don't quote me on that though).

The book itself was paperback, rather thick, and the front cover if I recall correctly, was of a well, from the point of view from someone who was walking towards it out of a building. I may be way off the mark here though

Again, if memory serves, I believe the book title was a single word, but my memory can be atrocious

I read it approximately 10 years ago, and even then it was an old book. It certainly wasn't age appropriate at the time, something more suited for young adult than for young teens. I originally found this book in my mum's bookshelf

I hope this is enough