loli = undeveloped + cute
So, it's not precisely the matter of declared character's age, but the way she's presented. In other worlds, if explicit focus is put on some prepubertal traits of girls with overall attractive appearance, we can start counting points on the scale of loliness

Funny thing is that formally even Lina Inverse is a loli character

/face palm...
the majority of us guys like big boobs anyway...
that an elf? i noticed the ears and w/e but didn't really be like " oh wow she really is a big breasted elf."
Well, not all the guys are brainwashed by media

In order to have natural big breast, girl should be of particular body type, which is quite different from being slender. If you want a thin or even frail girl girl with huge breast, there's only one way - silicon. Take a look at classic paintings - artists back when also paid tribute to large breasts (which is instinct based preference), but the women there are obviously different from nowdays models.
Elves are described as graceful, almost frail creatures with delicate features, and this is exactly the image I like. Naturally, big breasts have no place in here, as well as silicon, because elves are pretty close to nature and won't go for artificial adjustments
