You know you're obsessed with LOTR when ...

[NightKnight]

...you can't sleep, and instead of counting sheep you start reciting the entire lineage of Elrond & Co. and trying to figure out exactly what fraction elf, Maia, and human everyone is.

I did this for Arwen. She is:
40.625% sindarin
17.1875% noldor
12.5% teleri
7.8125% vanyar
12.5% Beor's house
3.125% Hador's house
3.125% Haleth's house
3.125% maia

Of course this also applies to Elladan and Elrohir.