Agent Richard07 wrote:
I also noticed that she knows an awful lot about the library. I wonder if there's anything to that. At first I thought she might be a reincarnation of someone who was there and she was somehow aware of that.
Or, she's the granddaughter of Aang and Katara and the grandniece of Sokka, and thus is familiar with the tales they passed down to their family about their experience in the library. We've known as far back as her first appearance that she has great curiosity about history, including the events that her grandparents lived through in A:TLA.