Hi JordanThe most beneficial for your mother(I am not a CPA here by the way just a real estate investor who has had a great one who taught me alot about the tax code) from a tax standpoint would be to use the Fannie Mae or Freddie Mac programs on a 30 year mortgage term, which allows the highest deductible interest payment and the maximum amount of monthly cash flow. 

There's one manufactured home that I found that sold in 2014 for $23k, it was a Fannie Mae property.

Fannie Mae or Freddie Mac) there is a minimum loan amount of $50,000.

They are multifamily, yet Fanny Mae considers them in the same basket as SFR when it comes to loans.

I can finally originate Fannie Mae HomeStyle Renovation Loans, and I'm really excited!

I found a home at a reasonable price that foreclosed to the lender(Fannie Mae).

Buying Ginnie Mae loans even in default carries with it requirements for servicing.  

To be more specific her potential brokerage prohibits purchasing homes from HUD, Fannie Mae, Freddie Mac and Wells Fargo because of corporate relationships. 

This Friday, we are settling on his most recent Fannie Mae purchase.

Fannie Mae HomeStyle.15% down tells me it's a SFR investment property and you are using Fannie financing anyways.