Everyone likes difference things styles. Yet some don't care how mature they get in age they wear thing not appropriate. Most people won't say anything. Some may I'm sure.
in my opinion knee-length is ok for a short skirt that way u feel comfortable about not revealing too much because of your age but of course, everyone's opinion differs that is just me speaking for myself.
A woman should dress decently and modestly at all times. So a short skirt for women of any age is a no. People should learn not to expose any part of their body all in the name of dressing.
It is a matter of personal preference and opinion. What is considered to be a "short" skirt for someone over the age of 40 will vary from person to person. It is generally recommended that mature women avoid skirts that are too short or too revealing. It is best to dress in a way that makes you feel comfortable and confident.