SOLVED. YA family moves to new home and sister is diagnosed with cancer (I think). Friends include a photographer and a couple the MC thinks are living in sin. [s]

[Amy (Other Amy)]

This one is mainly about the sister who is not sick coping with the fact that her sister is. Details I remember: the sick sister is always drawing pictures of brides and the MC, who is artistically inclined, gives her a lesson on proportion because the arms are too short. The MC had her eye on a particular room when they move in but her dad claims that room to work in (I think the purpose of the move was to get him to a quiet place to write). The MC ends up sharing a room with her sister. She makes friends with an adult photographer and they study photography together- I do not recall any hint of romance anywhere in this book. They are also friends with an adult couple (I don't remember the connection) and the MC is anxious because they aren't married (view spoiler)[but it turns out they are (hide spoiler)]. The main thing I remember in the end is (view spoiler)[The photographer has a showing and the last photo is of the MC and she tells him he made her beautiful and he tells her she already was (and I still didn't get any romantic vibe out of that - very much a coming of age moment). I'm pretty sure the sister dies and the MC and her parents are going to move again at the end, but I can't remember clearly. (hide spoiler)] It was a bittersweet story about a girl growing and I would love to find it.

[inaword]

A Summer to Die

[Amy (Other Amy)]

That's the one. Thank you!