Seeing all these Facebook posts about choosing the books that influenced you got me thinking about a book I read when I was about 11 or 12 so would have been mid 80's. Not sure if it was a kids book though - I read some weird stuff. The tricky one with this is that we were living in the US at the time so could be unknown here.
Here's what remember - a toddler brother or sister accidently drowned in a pond at the bottom of a garden and the main character is blamed/blames themselves. There was something about a rose bush - I think 'rose' might be in the title and I think it's set in Brooklyn or at least some of it is and I think early to mid 20th century. Don't know if it was fiction or a biography.
Not much to go on I'm afraid - I will be amazed if I can find it but thought it's worth asking. Or it could be my brain remembering a mish mash of books. Any ideas?