What's the Name of That Book??? discussion

Quite a while ago I read this book which I barely remember but am pretty sure it was good! Three siblings get stranded on an Island of some sort, I think it was and older sister, a younger brother and a baby. Its possible they were trying to find their parents after being separated after a shipwreck and at some point I think they lost the baby. I also vaguely remember a possible village built in the trees by something. Was a bit of a thick book from memory.

When did you read it? 2 years ago, 10 years, 40 years? I assume this is fiction (you never know). What time period is it set in, what island or ocean? Children's, YA, adult?

yes I think that might be it! thankyou very much

Hi I’m really sorry, but I’m trying to remember the name of this exact book, did you ever remember what it was? X