Actually, Namine looked like this Because she wasn't created until Sora unlocked his heart inHollow Bastion (or, more probably, when she lost her heart during the KH1 prologue), so technically she's still in the age range that we would consider a child to be, as age is a measure of the time since birth. She just has the maturity level of Kairi, but presumably that's just what happens when a human-like Nobody is created. Sora and Roxas are separate entities, so it would logically follow that Namine and Kairi are too. Spoiler But this is the Spamzone, so we probably shouldn't be too particular about canon.
Seriously though, think about it. They didn't include Zack pre-BBS because he was killed before VII and therefore could only make sense in a game that takes place in the past (i.e., before he dies). ...But Aerith, who is killed during VII, is alive and well in the series. Am I the only one that sees a problem with the logic used here?
See my earlier post. :B "Logic" and "canon" cannot be ****ing used when describing things that can be applied to KH.
OR IS SHE? KH is a massive paradox, the more you think the less you think and the less you think the more you think. But if you stop to think you stop thinking and if you stop thinking you get fanfiction ideas.
This is not a paradox, because you said it is a paradox there for it is true, and because it is true, that means this is not a paradox but the univers imploding on itself