Give her the Artie Lange example. Many years ago when he was just starting out show business he got a roll on Mad TV. A guy went a registered the names of every cast member on that show. Several years later he wants to start a website and the guy wants 50K for the domain. Artie could fight it, but instead ended up buying a hypendated version.
You can just say, "Would you rather I thought ahead and bought it and am now giving it to you for free, or would you rather I didn't and let someone else buy it and now want a lot of money for it. I did you a favor here."
Also, a friend of mine's wife has a fairly common name. The domain for her name redirects to a celeb porn site
