What is this book?

[Lightshines]

I know you lovely MNers are really good at these puzzles
Here is what I can remember:

I read the book probably 10 years ago and it was fairly contemporary
Paperback had an orange cover
Written by a female journalist

Story was of a teacher who discovered that her partner/colleague is a paedophile. There is a school trip to ?Venice.

Any ideas?

Notes on a scandal? Although doesn't quite fit with your description I'm afraid.

Libby Purves, More Lives Than One.

Yes, yes, yes! Thank you so much BreconBeBuggered .
Are you Libby Purves?!
Or have you read the book and it stuck in your mind for some reason?

I want to read it again.

I am not Libby Purves. My shoulders would never stand up to all that sailing.

I recognised the orange paperback...Actually, I was thrilled to finally guess a 'what's this book/film/song' thread for once.