Fantasy novel with that world's version of a gypsy

[maidmerien]

This has been driving me nuts for years. It's a book I read when I was a little girl. All I can really remember about it was one of the two main characters was a gypsy and she could tell fortunes. I remember that she was better at it than her mother and she could do magic through meditation - breath in one nostril and out the other. I also remember the book started with the villain going to visit the girl and her mother to get his fortune told.

I think there was a second character who was a boy and there was an adventure to save their world or kingdom or something similar. I know it's not a lot of information, hense me never being able to find it on Google. >.< Any points in the right direction would be wonderful.