A Swedish children's book by author
Astrid Lindgren is called "Ronja, Daughter of Thieves". It is a great book which has also been made into a film. I believe it was written in the 1970s or '80s.
I know this probably doesn't help you much, but I thought I'd mention it. As a Russian name, Ronia would seem like a pet form of a longer name. I've emailed someone who might know; when I receive her reply I'll report back here.
- Tue