Many times banks will start to count rental income as fixed income (usually around 2 years of solid rental return), which will further reduce your debt liability.

Hopefully, your mother can reduce the value to each of you by subtracting back all the expenses over the years. 

There are 2 numbers being thrown around in this thread and I was about to clarify it but you beat me to it ;)There are 2 types of returns one gets from real estate investments (or really, for any investment that produces a yield or dividend or income):Cash on Cash Return - is the cashflow you get every month divided by the cash you invested to acquire/renovate/stabilize the assetandInternal Rate of Return - is the total of the cashflow and the net profit from sale (including loan paydown) divided by the cash you invested to acquire/renovate/stabilize the asseLarge apartment complexes in decent areas (A/B), specially when you're trying to do a value-add, will produce 6-8% Cash on cash on YEAR 1 (or even lower) but it increases significantly on year 2 onwards as you're able to increase the average rents/ reduce the expenses through improved management efficiencies (my stabilized project CoC is about 12%).You can get higher CoC (10% and up) for sure (even on Year 1) with apartment buildings in C/D areas but generally, you tend to get lower IRR due to the lower net profit from sale due to the higher cap rate.And as far as the advice never to get a property with very low (or negative) CoC on year 1 - well, I agree and somewhat disagree.I agree specially if you're a newbie investor and has no passive income yet.But, once you get passive income, you can work on heavy repositioning projects that might not cashflow on year 1 BUT the cashflow and the IRR is significant once you turn the project around.

We are putting some money into a few renovations and making it a little nicer place for our future tenants, and to hopefully reduce problems we can for see from dealing with the property for 5 years now. 

@Denise Gold, a few ideas to help reduce risk:Upfront Rent: Have them pay the first 2-3 months upfront, plus the security deposit.Increased Security Deposit:  If they are against upfront rent then consider increasing the security deposit to your area's legal max.Proof of income/funds:  Have the co-signer provide their latest 2-3 bank statements to prove they can afford it.Roommates: Are there any roommates for this individual or is it a single?

Reduced pricing is also a sign.

For example, if you have 20k auto payment with a 1k a month payment it might make sense to pay off the 20k to reduce your debt to income to qualify.Finally, you can use a debt service coverage ratio (DSCR) loan to access the equity in your non-owner occupied properties.

all reduce overall demand. 

As far as the Sedona real estate market goes, non-STR properties have taken a hit and reduced in value.

I alos suggest you start gifting the maximum amounts to each, if you have not been, to help reduce the estate.