This has been addressed by others already, but the clothes and breasts aren't the same either. Nancy is probably a G or H cup, but the image from behind looks to be more like a D or E cup. Nancy's skirt is sheer, so you'd be able to see the garters from the other image, but they aren't there. The only valid similarity that keeps being brought up is the similar cybernetic arms, which could easily be explained as starter equipment for two people who haven't been to the server before. None of the other supposed similarities actually exist between the two images. The hairstyles are very different. The only clothing similarity is that they're both wearing skirts, but the skirts themselves are very different. The bust sizes and shapes are very different. We have an example in almost every chapter so far of users signing into new servers being given default beginner level clothes/gear appropriate to a server, sometimes even spawning into a server wearing it, so the one actual similarity amounts to nothing useful to base any comparisons on. So maybe it is Dalia, but the only conclusion that could be definitively drawn from the two images is that they can't both be Nancy.