I spotted this cover in Oct. 2003 but was not sure that they were the same girls. "Sisters" is obviously them but in this cover, which names them, it isn't so obvious.
http://img146.imagevenue.com/img.php?loc=loc11&image=15016_102103.jpg" target="_blank" title="http://img146.imagevenue.com/img.php?loc=loc11&image=15016_102103.jpg">http://img146.imagevenue.com/loc11/th_15016_102103.jpg" border="0" />