They've certainly got the same fashion sense in the least. Though to be honest, I don't picture her with hair that blue. This particular Kappa has hair that is quite lighter than Nitori's in that chapter.
Mr_GT said: So you're saying that So I guess that means that all Kappas look like in Gensyoko.
I don't think so. In the manga, they just give us a glimpse of the kappa with the same occupation as Nitori's. That's probably why they got similar appearance. We haven't see them inside their village, haven't we?