What's the Name of That Book??? discussion

I read this book between 2002 and 2007, as a paperback. It was probably first published earlier than that and it was part of a series.
I read a German translation, but I believe the original was English. The author was a man, If i remember correctly.

One of the protagonists was a girl who was accidentally transformed into a woman by magic. I think she had magical powers that she couldn't control very well. There was a spell-gone-wrong scenario and she accidentally aged a couple of years during mere minutes. She went from early teens to early/mid twenties, I think. After the spell, someone covered her with a coat or shirt, because her clothes were lost or didn't fit anymore.

There was also a man who lost one arm. He was kind of a love interest of the girl/woman. (Seems a little iffy now, tbh.)

There were also other protagonists, it was multi-POV and part of a series.

That's about all I can remember.

Found it! Well, that was quick. It's The Book of Shadows by Stan Nicholls.

Thanks for the update, Sarah!

The Book of Shadows by Stan Nicholls for the link