To the laborers sitting in the waiting room of a temp agency in Elizabeth, she is simply "La Se ñora." She's the woman to see for a warehouse or manufacturing job at plants just a short drive away. Even at agencies that hire temporary workers, it is against the law to hire people who entered the country illegally. Federal laws re quire employers to verify a worker's status with identity and work authorization documents, such as a Social Security card, before they hire someone. But in May, Dilcia "Dee" Mem breno at Nielsen Staffing Services -- La Señora --made an...