HER CHARACTER Undercover narc Syd Burnett, sister to Miami detective Marcus Burnett (Martin Lawrence) and love interest to his partner, Mike Lowrey (Will Smith).

HER QUALIFICATIONS She's already handled bad boys LL Cool J and DMX in 2003's ''Deliver Us from Eva'' and ''Cradle 2 the Grave.''

FUN FACT Growing up with a military dad prepared Union for dealing with hot-tempered directors like ''Bad Boys''' Michael Bay. ''Once you go through what I did with S.E. Union, everyone else pales in comparison,'' she told EW. ''Michael telling me my makeup looks funky is not going to make me cry. Just do my eyes over.''

WHAT'S NEXT In the 2004 romantic comedy ''The Breakup Handbook,'' Union jilts fiancé Jamie Foxx, inspiring him to write a how-to-cope best-seller.