Tell her she is already pretty. Im Not sure how old you are but boys are basically immature and stupid. Some grow up and stay stupid. They probably like her but dont know how to express it. When I was young this boy who had a crush on me would stomp on my foot. In 8th grade a boy who liked me held a lighter out at me and flicked it on. I ended up punching him in the face later. The stories go on and on. anyway, it is best to just ignore those boys. One NC it is all about being comfortable with who you are and not caring as much what other people think.