If you have arrived here it is that your knees do not like you: you have them swollen and with excessive volume. However, if you are looking for a miraculous exercise to reduce them, wake up: it does not exist. The point is that "wide" knees are the reflection of something else more important: excess fat. So what you should do is abandon specific exercises and look for others that represent a comprehensive plan for your whole body. Although there are also foods that will help you deflate your knees.
Due to a genetic issue, women are often predisposed to 'store' more fat on your hips, legs and thighs. That is why your knees give you away and warn of a bigger problem. The passage of time and inactivity can make your knees accumulate tissue, also becoming an aesthetic problem. So before you banish shorts and miniskirts from your closet forever, look at all you can do for them.