happy belated birthday Jean! I cannot BELIEVE you are 51. Seriously. Cannot believe it. I think you're lying. You look a good 20 years younger.
I think the skirt fits great and I like the wash, but I'm going to stick to my guns and say show off your lily white knees. I think it would look great on its own, and I think you should look into incorporating more pencil skirts in your wardrobe because they really seem to flatter you.
I am honestly not in love with this ensemble as though. I think it just divides you up into too many sections. I think the key to making the skirt and leggings look work for me is to keep everything fairly low contrast.