We were able to get a new appraisal done, and lowered the price by $19K, and quickly got an offer in hand.  

I would imagine so long as the rent is not hugely undervalued you would end up coming out ahead fairly quickly though by not having to deal with the cost of vacancies every year or two depending on the situation.It looks like all this may be irrelevant though as their agent has stopped responding.

Again if your parents are really worried, I'd say do a quick consult with a RE lawyer (I am not one and don't play one anywhere).

At least in my state filing of probate does not stop a foreclosure automatically so some other action may be required... and quickly!?  

So, for a quick background on myself, I am a recent college graduate living in Atlanta, GA, currently working at a marketing agency full-time, but have become extremely interested in pursuing some sort of real estate investing.

Also was wondering how quickly this process normally is of obtaining equity?

It seems that they may be a quick way to get comps and rent ranges. 

I am trying to attract high end renters for higher rent properties.

For being your first deal, renovating 4 units in 4 1/2 months is extremely quick, so you should be happy with that success.  

You can do a quick check on google, and just search "tenant law in MD" and it should give you the law pretty easily.