@Scott Smith thank you for the solid direction.

I am still trying to formulate a couple solid questions I have, so I can be more direct. 

We will underwrite the building using solid/conservative information on gross income (what are market rates, can we raise rents over 2-3 years, what reno needed to get to market, how do are units stack up compared to others, what is market vacancy, etc.), what we can achieve not what the current owner has done.   

A good Realtor will expose it to everybody in the market with MLS listing and a solid marketing plan.Either way, unless Mom is a trained negotiator, she's going to be up against one who brings the buyer. 

Milwaukee does have a disproportional amount of renters and a solid inventory of low-priced housing.  

Any suggestions for a lender in the DC area (looking to purchase either SFH or duplex in Baltimore) for a mortgage under $100K and a solid credit score?

I have 9 single family rentals, plus my primary residence, and I have solid W2 income.

From that info you should have a solid idea of what kind of rent and renters your building will attract.

With the class properly assigned to each expense and income transaction, you get a solid bookkeeping package.  

I will try to use the wholesale calculator successfully to make sure I have a solid offer which doesn't come off disrespectful.