Rentals don't go on Sch C unless they are defined short term rentals with significant personal activity on the rental properties, like short term RE, hotels and possibly AirBnBs.

The point of the the RE Pro designation is to get RE losses on Sch E to be non-passive and thereby currently deductible. REP doesn't turn the rentals into Sch C.

A W2 wage earner can be an REP if they're an employee in an RE business(like a RE repair or RE lawyer), even one not owned by them. A Sch C owner of a broker business can be a REP.

If you spend money for a business deduction and it is related to your one or more Sch E rentals you can allocate it between the properties. Emphasis on whether or not is it legitimate business deduction for the rental properties.

{Personal opinion only-"She has set up numerous SMLLCs and I need to ask her more about her strategy." - This is a lawyer's scam. More legal fees than she needs to pay.}