I think that the most likely scenario is that this is just a normal girl who happens to be named Kaguya and so it's made her a little eccentric.
That does mean that I'm extra looking forward to her interactions with Tsukasa, the real deal.
Wow, my heart actually skipped a beat when I saw the swing set, that's one of my favorite Yotsuba chapters. I'm more than satisfied and we still have four more chapters to go!
As always the salt of the haters continues to sustain me.