Spidey976
Super Freak
She is not close to being heavy. Unlike the 90 pound weaklings you mentioned this statue looks build enough to kick butt.
Electra is a world class athlete and assassin, but she isn't an MMA brawler or a Kardashian. She has a lithe frame far more along of the lines of what Shadowflax posted above. However, Peedi over at SF made the point over at SF
In the minority here but the pose doesn't bother me at all.
As for body, you can find all sorts of depictions of any character by any artist but Elektra interestingly enough seems more consistent than most characters, and Marvel does have official heights and weights which I think are even more important for sculptors to follow when aiming for 1/4 scale accuracy (although I think comic artists should also stick to the officials as well).
Elektra's officials are 5'9" and 130 lbs. Not sure if it's on purpose but Greg Horn's work of her seems to keep in line with that.
Quick image search got this, Katy Perry is just 1 inch shorter but a decent guideline for Elektra I think.
And it'd be cool to make the face look more Greek since Elektra is Greek. I like the costume choice though, it's better than the nonsensical bands she wears. I'm normally all in for comic accuracy but I always imagine Elektra putting those bands on one by one and how ridiculous, time consuming and impractical it'd be.