Everyone mentions it. It’s not even a smile, but it says something is very wrong with her. And is quite disturbing.
Someone upthread who is local says she’s know to be anorexic. Which means she has a very bad self-image. That overdone smile is probably a compensation attempt. Some who suffer from this malady hear voices that tell them they are ugly and no good and they should kill themselves. It’s a very unpleasant condition.