Fantasy, adventure, heroine is running away with a group of friends

[Gogol]

I read it around 2019-2020
SPOILER
The only scene I can remember is when they’re camping, but they’ve been driven by the enemy to camp somewhere they shouldn’t have and mages are creating a snow storm, to kill them, the heroine says she can find them so she and another character (I can’t remember if it was the hero who accompanies her or not) track the mages and kill them but when they get back to the camp they see the mountain people have surrounded their friends and want to execute them. She’s familiar with their customs so demands a sort of trial, she knows her life would be forfeit if she fails but she demands that her friends be allowed to go their way. They have to be taken back to the mountain people’s castle for the trial where they can eat food and afterwards the heroine should dance a specific dance with one misstep on magic stones which sting bare feet. The dance should be danced in bare feet. She dances without even one mistake and when she finishes, she realises the person who is judging her dance is her former teacher who taught her to dance and she’s the leader of the people in the castle. They meet back in the quarters given to her and her friends, and I can’t remember anything else.
I think the writer was a woman?
I read the book in English.

I hope I’ve done everything right and thank you so much for your help and attention.