What about moving her arms positioning. Right now they are just out to the side, moving them more behind her could give her more of a shy or reserved body language. Its a small thing, but I think it might go a long way. Her more open body language with her arms out, plus the more see through shirt make her seem much bolder and confident, vs the much more reserved shirt and tucking her arms in makes her seem more timid.
Also about the heights, hearing that I used snipping tool to cut out her box to put her next to several characters to directly compare(used the ragged cloak version as its just ever so slightly shorter). And yeah your right, she is as tall as Alissa (which surprised me). bell is much bigger, as is pixie, though with pixie though her head is higher so is her crotch by a decent amount, so I guess I got the feel Pixie was just higher up in the frame so it was just different levels of zoomed and perspective. I guess I didn't realized the portraits were all the same level of zoom and perspective. Some feel more zoomed in then others, before putting them side by side I though pixie and bell were every bit as short as Cassie. part of what gave this feel I think is that the portraits aren't the same level of zoom as the character portrait, so I just didn't assume they weren't standardized, or wait are they the same level of zoom as the character, if so man the player is small.