I'm glad to announce that my sister was much more susceptible to TTT than FotR. She asked some questions like is Gandalf the White a good guy and why did he fell into the abyss in Moria (yeah, we all know the answers, of course, but I was quite impressed by her attempt to follow the plot!). Next day (she still didn't want to watch the both discs on the same day) she proposed herself if we watched the second disc! Oh, happy day!