They are most likely not cash flowing, probably it is only equity pay down they are getting and appreciation as added bonus.

It was built 10 years so I wouldn't think anything major would have to be done to bring it up to code.I'll probably start reaching out to other ALF's and advertising it for lease to see what happens. 

Our family probably needs about $6,000 a month to live off of if that matters.

I'll probably be the minority here, but I would give them a slight reduction in rent or subsidize their electric bill.

I've been flipping for 15 years so can probably direct you to someone. 

It would be a shame to sell the 4 plex just to buy another house (probably a single family from what I understand). 

By looking at her credit report, it is clear to me she’d probably have issues paying her rent, but that’s where I didn’t know how much you all rely on a co-signer for.

Although if you use only your own money and lend only to investors you will probably get away with it.

In my case, we do no deny tenants based on bankruptcy (only evictions), and this tenant would probably get a thumbs up, pending employment verification etc). 

It seems to me that even in the perfect situation, where I get paid like 12% interest rate with no chance of default, and I get a HELOC with around 6% interest rate, I'm going to have to pay taxes on the interest I collect, but I cannot write off the interest I pay, and it will probably not be worth it.