I read all three volumes to each of our three children, beginning to end. It's a big family thing. We have debated the merits of Tom Bombadil's poetry, how we would have dealt with Saruman, etc. etc. So we're really into it.
I went with our 15-yr old boy, the last one left at home. We were ambivalent, because we feared it wouldn't be true to the books, which we love. And we agreed that if it wasn't really good, we'd leave. We stayed for the full, three-hour show, loved it all, would happily have stayed to see it again, we'll certainly go again when it hits the theaters.
The characters are exactly the way we imagined them, the places are just perfect, and I knew everything was going to be fine the first time I saw the Shire, because it's really the Shire, and Bag End is really Bag End. Even Bree is really Bree, not some Hollywood version, if you see what I mean, it's the real place.
And so it goes, a perfect rendering of Tolkein's universe, and it's not a showoffy film, you don't ever say to yourself, "wow, what a great special effect!" You just enjoy the story, which is one of the best legends ever, and you accept the reality of what you see on screen.
At least we did. I don't know how this film will strike people who don't know the story, I hope they love it. And there are certainly plenty of scary moments, because the monsters are fearsome and some of the creatures, like the Dark Riders, are likely to visit children at night, just like the evil witches in Snow White or The Wizard of Oz. But there is no gratuitous violence, no--zero--foul language (quite the contrary; the use of language is gorgeous, and it's great for children on that score), although people do die, and there are big battles.
Hope that helps.
As for my daughter, my main concern would be gore. I knew (or at least think I know)that language/nudity would not be a problem and we are very careful with that, I just didn't know how vividly the portrayal of the battles with the Orcs would be, primarily toward the end when the fellowship breaks up.
Thanks again for your review. I'll try to see it myself before I take my daughter though, just in case.