Grade 5 class novel is one I'd have saved for 12. Do I say anything?

Her class has started a novel for the term. It's well written and on plenty of lists for this age, I checked. It also has a war in it, a family separated, and a chapter near the middle that I found hard going myself. She read ahead over the weekend, as she does, and came to me at bedtime with questions I hadn't prepared for. She wasn't scared exactly. Unsettled. I don't want her pulled out of a class book, and I'm not keen on being the parent who complains about a reading list. Do I tell the teacher she's ahead and a bit shaken, read it alongside her, or leave it and let the class discussion do its job?