Can I tell you a story?
When I was 24 years old I worked in the garment district in NYC designing for a textile mill.
We had an intern in our office named Lakisha. She was a confident teenager and spent her summer and after school hours working with us.
Lakisha had a problem. She loved wearing short skirts but was so sick of men looking up her skirt while walking up the subway stairs.
She refused to change her style for those idiots.
She shared a secret with me- she always wore bike shorts under her skirts.
It seems so simple but it was Lakisha's ARMOR against men.
As an adult woman, I now use bike shorts as a "MAM"- Middle Aged Modification- they stop my legs from rubbing AND they smooth the bumps AND they prevent anyone from seeing up my skirt!
So go ahead and wear the "slightly above the knee length dress" with confidence- add bike shorts!
Cheers!