She can't afford what it's worth.

It can be done; but the whole idea behind OS investing is to be able to buy properties with enough cashflow so that you can readily afford a PM.

@Adam Gollatz hit it right on the head. the most 'affordable'  or 'landlord friendly' markets are listed above.

Since the down payment % is so low, you can afford to buy a multi family with 3 or 4 units.

We've decided on Atlanta because of the market growth, demand, and (relatively, especially compared to NYC) affordable prices.

The tax incentives for first time home buyers to help with deductions of mortgage interests and so on if you decide to get a mortgage and wait up to 30 years to finally own your home which by then you are probably in your 60s.Anyways down to the real question here.For a first time home buyer trying to purchase primary residence home, does it makes sense for me to buy the house all cash if i can afford to do it?

If you cannot afford to buy today you might negotiate a ROFR in your lease where you have firsts rights to purchase if the owner every decides to sell the real estate.If you would own one space in a condo type for office or retail you have to be really careful with WHO is running the association because you will likely be a small percentage owner versus the overall spaces and have more limited control and input to what happens to the project as a whole.  

Economies of scale sometimes push people to own more so that they can afford to do less.

I considered to just keep bumping their rent. but I know for a fact they can't afford it. 

I'm in the process of vetting lenders who can help me get started on my REI journey getting my first property/mortgage.Obviously, before I can buy I need to know what I'm pre-qualified to afford.