One thing about aging is that your weight tends to go to the waist and hips for women instead of the thighs and rear as it did when younger,. So if you had well shaped legs as a 20 year old, they will probably still look good at the same weight range when you are 40+. If you are not burdened with vein issues.
For myself, I am always up and down the stairs in my house so I get a built in workout as mom, at least for my legs.
I will wear a short but not tight casual skirt in the summer, about 3-4" above the knee. But really, its more in style right now to have a knee length skirt anyhow. I avoid wearing shorter skirts that look like they are for a junior, or are dressy or racy. They work for me only if they are casual and sporty. Like an E Bauer style. My mom wore this type of skirt up until her late 50,s.She has cute legs, with small ankles, nice knees, just a few spider veins, nothing big.