This is a really beautiful picture, the composition and the colors really work together! I do feel the need to point out one detail I think could be done a little more naturally, the chest of the brown-haired girl seems to be sticking out at an odd angle. I know exaggeration of a girl's breasts is often done for beauty purposes, but I think it would be better to smooth, shape, and angle the chest a little more naturally. It may not call as much attention to her chest, but the way her breast looks currently seems awkward and not-quite-right. Not many real people have breasts so voluptuous.
I love this one, especially Vaporeon. ;A; It's pose and expression are so perfect! I also love the placement of Charizard and the angle you chose works so well! The characters are both really cute! I'm tempted to make my new OC blonde now. xD