Start small and pick a pace you're comfortable with (1 a year, 2 year, etc).

Honestly, I'm not sure I'm comfortable with her having keys.

We are not in a place financially where we feel comfortable investing (yet).

What do you feel most comfortable with?

Then I would factor in which property is more comfortable to live in (do I like the unit you come home to). 

Go to as many groups as you feel comfortable with.

I'm comfortable with anything from a single family up to a 4 unit, hopefully in the Southern Berkshire County area.

We have asked the tenants if they would like to buy the house but they don't have the money for a down payment and having just had their 2nd child they are starting to outgrow the house. 

My day job suffered during those 3 months and now I have a wife that's 8 months pregnant with our first child.  

No  way I could be comfortable with doing that, I've had way too many people who've sounded good over the phone and turned out to be atrocious once I started digging into the background.