Thanks, Xiaobaitu,
Some guy said that the relationship between contractor and employer are independent service provider, and the employer therefore can't provide support for her H-1B. There are some contractors in my wife's company, and they said their payroll is actually on company B, and they are out-sourced to her copmany. Does that suggest that my wife need to file another H-1B with copmany B if she wants to work as contractor? Mant thanks!