I'm 5'0'' and 129 lbs, got size small. They fit perfect. I wasn't sure till I tried them on. They are a bit long, but that's OK. I would not say they're too thin. They seem to be well made. That they fit is a true blessing. I've ordered two more pairs. Just hope they hold up to washing.
So far I'm pleased with my purchase. Material doesn't feel rough. Very cute and comfortable.