Aww she's just so cute ! It is even hard to tell that she's experiencing ache, her cuteness makes it nearly invisible ! I love just everything about her appearance - hairstyle, face, tiny mouth and face, big shining eyes, T-shirt... I even like a font in which a phrase in bottom is written . It matches here perfectly, I think .
Very cute artwork...and I know how your sister feels. Growing teeth (and some other body parts) can be painful sometimes. Lucky for me my teeth have already grown. Hope she takes good care of her teeth.