I just realised two things about Arwen when I was reading the Silmarillion the other day. Everyone else probably knows this already, and they'll be like, "Der!" but oh well.
Here they are:

1) Arwen is part Maia. Not a very big part, admittedly, but it's still cool! Her great great great grandmother (I think that's the right amount of greats) was Melian the Maia.

2) That Arwen is related to Aragorn. Arwen's uncle, Elros (who chose to be numbered among men) was one of Aragorn's forefathers. So they would be cousins, removed about 50 (maybe more, I don't know, I didn't count) times. Is that right? Anyways, Aragorns would be so far away from Elros, that it's not gross. And that also means Aragorn is part maia, but even less than Arwen.

Anyways, thought someone might be interested!