skygiants

I'm not quite sure how I found it, but I think it was by searching for the author, who also wrote a YA fantasy/romance (Of Two Minds) that I really liked as a kid.

That's neat! I don't believe I have read Of Two Minds, but the author's name looked familiar enough that I hunted down her website and it looks as though I read Lisa/Lisa's War, because I definitely remember reading a middle-grade novel about the Nazi occupation of Denmark that was not Lois Lowry's Number the Stars (1989).