Also focus on what happens to the characters after LoTR. As Firefoot said, don't mention too many names. I also think you should talk about the Arwen and Aragorn tale- it's a nice wrap up and also the girls will love it; one of those little semi-tragic romances that is coming to an end. If you want, you can also talk about what happened
before LoTR and a bit about Morgoth, though I wouldn't go into great detail about that. Don't put too much faith in me, because I'm only 15
.