I've been wondering the same thing myself, actually. Apparently Eevee is a Pokemon that evolves by a whole bunch of different methods...I was at the Goldenrod Department Store with my sister, and they have so many different stones there to evolve Eevee with! There are even Grass ones and Ice ones! ...But I don't want my Eevee to feel pressured to change or anything, you know? There are so many different options that it's a little overwhelming, but I don't want Dawn to think that she has to evolve anytime soon.

...As for Odin, my Kirlia? He really wanted to evolve the second he saw a Dawn Stone. I think only male Kirlia react to them like that, but he's very protective of Elsa's Kirlia, you know? So after he saw it, I guess he figured a chance to get stronger...it was something he really wanted.