I've been approve by the bank and they are willing to loan 80% of the money, but I need to come up with the 20%.

As long as you mom can qualify on her own (with her credit score), I don't think adding you to the loan application would hurt even though your score is not good (but I would still double check that).

But now I don't have the funds for EMD.

Some actually did a deal or two, but most did nothing. 

,This situation might be very specific but I am needing help solving this issue.I have someone who would like to sell me their Airbnb House they currently have it under a VA Loan with the Local housing authority. it is assumable but would require me to put more down and would limit their use of the VA Loan until i refinance out of it.the Local Housing authority has been calling mortgages due to anyone they find that are owner financing homes while still having an active mortgage from them on. 

Thank you for your response but I am still confused.

I tend to migrate towards small multi family but am open to single family. 

Beyond that there are hard money lenders who charge higher rates to take on more risk... but they again start by looking at you, your skill set, and your previous experience in both managing your credit, as well as your real estate investment history.  

Having two open loans for the property is not ideal as that's double closing costs but maybe that is a fairly normal strategy?

My company does some short-term, but we specialize in mid-term rentals (1-3 months).