Skinny does not translate into healthy. I've seen many skinny people that were very unhealthy. (check out a drug rehab center sometime for all the skinny meth freaks and crack heads)

Your goal should be to be as healthy as possible and forget the judgements about fat vs skinny.

I get a little testy when I see the false dilemma of "fit vs fat", which is only a superficial assesment of health. The look you should go for (for a woman) is to have a hip to waist ratio of 0.7. This means if your have hips measuring 42 inches, a proprtional waist for you would be around 29 inches.