I think a snap decision about intelligence would have more to do with how she carries/presents herself rather than her raw beauty. Intelligence carries with it a form of self-awareness and confidence that is reflected in the appearance of the person, whether they are naturally attractive or not.
That said, I find it hard to accept overweight people as being intelligent. Being overweight signifies a lack of self-awareness and self-control that should come with being intelligent. Smart people have good ideas. It's a good idea to eat well and live healthy. [/tangent]