This means that someone who makes $43,000/year would now eligible to buy this room condo, and have access to a vehicle through which to build equity in an asset as an alternative to paying rent. 

Before I order a second appraisal, I would investigate an alternative lender.  

I'm looking for alternatives, I liked LandlordStudio actually but I hate the name, seems so impersonal to the tenants and not in their favor.  

Alternatively, yes you could sell, pay taxes on the gain, and use the proceeds to help your mom directly.Would suggest for you to talk to a CPA and a 1031 specialist to confirm your best move!

Alternatively, restructure the loan with equity participation for potential capital gains treatment at lower rates.

As you're looking at properties it's best to identify multiple potential replacement properties to give you more opportunities and alternatives. 

(Not judging the merits of the deal, alternatives, etc...)

Your goal is to build a passive real estate portfolio (we can discuss what passive means to you), so while I don't condone throwing $100k into a deal without even a basic understanding, alternatively doing so will teach you far more lessons than reading a book will.  

To avoid unnecessary liabilities, delaying acceptance or exploring a cash alternative may be the safest financial option.This post does not create a CPA-Client relationship.

I do appreciate that thorough alternative perspective.