Well I’ve been searching for this book forever and the problem is I can remember very few of the details. It was a book geared toward, er, young adults, I suppose, and I would have read it about… (gasp!) 20 years ago. I remember being very moved by it, but that’s about all I can remember, except a few minor details:
The protagonist is a young girl, probably about 10 years old. She has an older brother, named Matthew, but she calls him Monse - which is short for Monster. Matt/Monse dies in a freak lawnmower accident - I think he was stung by a bunch of bees that he disturbed while he was mowing, fell off the mower and… 
is run over. I can’t even remember the girl’s name. Anyway, it was basically a coming of age kind of story.
I’ve googled like crazy, and come up with nuttin. If anybody knows the book of which I speak, I’d be forever grateful!