paula hefner wrote an answer about CW-X Insulator Stabilyx Tight - Women's on December 17, 2012
I'm 5 ' 1" , but weigh about 130 and have similar build (muscular legs). I purchased these in a small and they are fine ,but a bit more snug than I think they should be. I would have prefered a medium, but since I found them at half price at TJMaxx I wasn't going to complain. (they had a large and they fit fine,but I think I needed more compressin. I think the small would be perfect for you.