Not quite four and a half feet tall Mystic Seas is one of the little people to be sure, although more proportionate to a child that simply stopped growing at an unusually early age in many ways she shows a few hallmarks of physical maturity beyond what her overall height would suggest.  Skinny even for her diminutive size it is unlikely that she weighs anything more than a third of the weight of an average adult.

Dressed in a hooded sweatshirt that is likely the only one she could find without some painfully cute picture on it in the kids section of some low cost clothing store she seems to be more than comfortable maneuvering her way around the larger and often oblivious gamers she interacts with so often.  Dodging them before they knock her over, and not really expecting them to do the same.

When the hood is down her face tends to be seen as more cute and attractive than pretty or beautiful, but it has the right kind of shape and dimensions to it for the youthful appeal look that many anime characters are heavily based on if she put even the tiniest effort into it, which she doesn't.