When it comes to Ciri's body, posture and all of that jazz - they're pretty good. I don't know why people are criticizing that she's too well endowed when there's not enough canon information about such things, and she's supposed to be a bit grown up. As to why she's walking around with a belt encrusted with green jewelry around her waist - that's a mystery. Not sure I like that though, early art that showed her riding on a horse next to Geralt had a better, more "medieval" and simpler costume IMO.
But there are some serious problems when it comes to her hair and face. Most of them have already been described in this thread so I'll just quickly point them out - her hair color is wrong ("blonde" is an important part of ashen-blonde, while at this point the hair just looks silver) and her facial structure doesn't really reflect her looking like a sort of the person with beauty that would be "childish" even well into her thirties. Plus I always imagined Ciri with long hair, but that's nothing more then personal preference.
Overall Ciri's okay, and I understand that we haven't even seen enough to really judge, but, shit, change the design to reflect the books a bit more.