How do I tell my mom I don't like my Birthmark?

As a kid, you dont really care about it, but lately i have. How do I tell my mom i really want it covered?? The thing is she has one too, and she was a model, and it never got in her way. So how do I tell her?? Please dont say you should love it, because i dont. How do I bring it up, and what should I say?? SOMEBODY PLEASE HELP SOON!!! Thanks.