Did she download the program using Explorer? If yes, then that's why there's a problem. Explorer is not 100% OSX compatible & can't handle dmg files properly. So tell her to use Safari (found in the applications folder) to download LW, http://www.limewire.com/english/content/download.shtml

The same problem happens to others who use explorer to download dmg files, but the file becomes an incomplete download. The system isn't sure how to handle the file & associates it with another program on the computer.