>>53228395
If it's zipped, it's a fitted shirt that contours to the body shape in a stylish way. If you unzip it, it's looser around the ribs and shoulders, presumably allowing for easier movement.
Pants are light and floppy, but turning to stone would make her a uniform density and weight, making it harder to move, and due to various folds, adding possible extra shear points or things to get caught on.