The word here is confidence. If she is not a confident person she will not be a confident lover. Usually people who are extremely beautiful may seem confident but are not. They usually have complex issues with their body. Average people on the other had either are working to get better and know it, or they accept what they are and roll with it. Usually the average person come out as the better lover 90% of the time. On the other end, those that know they have a great personality but have nothing in looks, usually can be great lovers as well.
I was with a woman once that was very scared about her breasts. She had cancer and they were removed. The surgeries were being done to replace them but were not complete. But as I kissed them and treated them as they should be she turned into a tiger in bed. One of the best lovers I have had.
Rookie Scribe