Children/YA girl learns she is a witch and solves a mystery concerning her father with a boy she met

[Linda]

I don't remeber a lot about the book but it's for children/teenagers. It's about a girl. It starts with the girl and mother driving to a family meeting which turns out to be something like a wizard/witch court. I vaguely renember the court being in the mountains. The mum is a witch and the girl also has magical powers or something like that. The father of the girl has been absent, I think she was told that he is dead or something similar but it turns out that he is alive but an evil sorcerer because all male witches become evil or something along those lines.
I think I remember there being an important scene in a cave and there being an island in the middle of that cave.
I think the girl meets a boy and together they learn the truth about a mystery concerning the "women good witches, men evil sorcerers"

I read the book in 2010-2015. It was a hardcover. The book seemed modern and not old. I got and read it in Germany, which is also coincidentally the language it was written in.

Does anyone know this book and perhaps its title?

[Capn]

Is it the same book Simone is searching for? Frozen ice sculpture/statue of father?
https://www.goodreads.com/topic/show/...

[Capn]

(Yes, same book)

Linda - is the cover the same one for you as what Simone has described?

Or do you remember a different edition?

[Linda]

Yes, it is the same book but I do not remember the cover at all :/