Quote from @Sushil Iyer: We have a SFH and a duplex that we own free and clear, and a duplex on which we have a residential mortgage.

The local area has similar homes without the land but closer to town with rent over our mortgage so I’m hoping it’s possible.

I was shown about a handful of their holdings in the Houston, Memphis, and Little Rock markets, but the cash flow and CoC returns were less than $100 per month and 2-4% after factoring in additional expenses like 7% vacancy and 10% maintenance per month to go along with 20% down and conventional mortgage.

I know conventional would be cheaper cost wise, but isn't her husband eligible?

That can be used to buy down the mortgage rate or reduce closing costs. 

Currently I have a mortgaged Duplex.

Wondering if the vacancy rate is higher in the area as it seems more advantageous to just buy a house and pay mortgages rather than renting.

We carry no balances and have no car payments and only one mortgage..

 I'm not opposed to subject to, but my fear is whoever I am taking over the existing mortgage from will not continue making the payments.You make the payments.

Mortgage is only less than $1400.