I have a client that is 100% shareholder of a C-Corp.     She is also has consulting income that she files a Schedule C on her personal return.   She also has income from serving on a board of directors- put under other income subject to SE tax  

The C Corp has employees, the Schedule C consulting income does not.     

If she were to set up a SEP or Simple plan for her consulting income.  Is her C Corp (Form 1120) considered part of a controlled group and now she must include the employees of the C Corp  for the Simple plan for her consulting income ( Schedule C- form1040) 

Thank you in advance for all your input.