I am 51, if that helps. We often had older books kicking around too.
I liked anything with adventure - Hardy Boys, Malcolm Savage etc.
This book featured a large forest and at least two kids trying to escape from something or with something, not necessarily sinister (I hate creepy).
They ended up in a boat, possible a coracle, and had to allow the gentle pace of the to lead them out of there. The river was winding back and forth, so they almost retraced their route back and forward as it meandered.
Anyone recognise this?
Booked seemed a very gentle form of adventure, and was possibly set in England.