Do you know the titles or authors of these books?
The first one is set in the past, (before the 1900's, sorry can't remember specifically, but if i guessed, I think it was the 1800's) and it's about a girl, whose father was murdered, and she thinks the queen and government are behind it. She's trying to run from whoever is after her and she befriends a boy (maybe a couple of them, not really sure! sorry) and he hides her and I remember specifically that in one part she joins the boys choir and pretends to be a boy, but I think eventually the choirmaster finds out...That's all I really remember, if you think you know what it is let me know!
The second one is set in "modern" time ( I think this book was written in the 80's or 90's) it's about a girl and I think her father got remarried to a woman who had two(?) children. And they are very strange and she learns that they don't age, and I think they want to kill her and her father, but the womans son feels bad and tries to save her...In the end I think he dies in a car crash...
I'm sorry I couldn't give you alot to work with, It's probably been about ten years since I've read these so my memory is sketchy...If it sounds remotely like a book you know of, please let me know! My memory may be off a bit!
Thanks soooo much!