Originally Posted by
Spring
My comment was just a joke..
Your translation of the line is completely correct.
However, "Čija si", commonly refers to - who is your father, who is your mother (in a situation like - this is a village, where everyone knows each other, so, if you tell me who's your family, I will know "čija si")
Since he is saying something so archaic like "čija si lijepa đevojko?", it totally doesn't occur to me that he meant that she belongs to a man (since she is a đevojka = an unmarried girl)