I'd just like to say that the face is quite cute
Considering that this is of course cartoon-styled, 6-7 heads is probably a decent height for a character. I think going above 7 might make her look too tall, I dunno. I'm fairly sure that in the actual games Krystal (and at least some of the other characters) are only about 4 heads tall.
May want to add a little more muscle to her arms, but not too much. (like Blaze said about the warrior thing; she should look moderately strong at least)
Considering the angle, I think the far breast should stick out from her torso a bit more? It doesn't quite look right considering the other breast and her torso. I guess if you want her to look sexier and more mature or whatever, maybe her hip/butt should come out a little more too.
The shape of her jaw/muzzle might be fine, it looks like it would be able to emote well. If you want her to look more mature you could try a less relaxed and more serious expression.
Just my two cents I guess