jesus for real. what did you guys think this would be when you saw the tags?
Your sarcasm detector needs new batteries.
it's not that i have issues with someone looking like her in elementary. she just simply doesn't act like one to me. it's too hard to see her as one.
I already briefly described one possible reasonable explanation you know. To elaborate on that, look at it like this - most strangers who encounter her will assume her to be much older than she is (like Tae did on first encounter) and treat her as such, which is going to be pretty confusing for someone that age right? (If probably also rather flattering, given how children tend to want to be regarded as "big boys/girls.") So what's a by all indications rather confident and go-getter sort of bright kid do about it?
Her figurative homework - try to research how a "big girl" is supposed to react and act.
Following this hypothesis, her source material would likely primarily have been such popular fiction (and probably youth magazines) as could be readily accessed... which one imagines has left her with a somewhat skewed idea of how to act with "grownups" and no real understanding of the various underlying nuances and significances. In particular - possible TaeVision™ embellishments nonwithstanding - those coquettish moves she pulls off with such aplomb may simply be an affectation she absorbed from such dubious research without any real idea of the actual meaning thereof, and just does because they elicit very entertaining reactions from adults in general and this tiny funny onee-san she recently made friends with in particular...