Since Simpson is a blond, I tried to think of a brunette or redhead to portray her foil. I also think that (since our yellow sun slows Jessica's aging, IIRC) then her nemesis ought to be someone older (but doesn't HAVE to be) - perhaps someone who started out as a contemporary of Jessica's (HS or college rival?) A few names that come to mind (other than those already mentioned) included.....
her HS singing rivals: Katy Perry, Spears, Adele, Mariah Carey, (too many to list them all)
her HS acting rivals: Christina Hendricks, Natasha Henstridge, Catherine Zeta-Jones, Sofia Vergara, Tyra Banks, Mary Carey, Shannen Doherty, Jennifer Aniston, Lisa Kudrow, Denise Richards. etc (a B-list actress?)
her HS athletic/cheerleader rivals: Cameron Diaz, ArielX, (maybe some moderately familiar porn star who was a failed athlete?)
her business (in her secret identity?) rivals: Bella and the Thorne sisters,
