It is because the Mouth frames are on the lowest tiles, you need to have them at least 16 pixels up.
I've made a small fix on your portrait, though you'll need to draw extra 8 pixels down for her clothing.
(And even though the first mouth frame has open eyes in it, it still works properly because the eyes frame are on top of the mouth frames.)
As you can see she's floating here, and that's why you'll need to draw 8 more pixels for her clothin.
This one also works, but it still looks ugly like this.
With her face sinking below the box. But you decide.