Contrary to what you said, a buyer who's reasonable to work with will have the attention of a good agent for far more than a day, but if the buyer is flitting around trying to work with a lot of other agents at the same time a good agent will wish them well and move on.

You can learn more about this space here and Gala games is not the only one with real estate for sale that is digital.https://app.gala.gamesIf this is confusing- it should be at this stage, but this is an opportunity that you will wish you participated in.  

Just my thoughts, wish you the best!

So my question...in the event the sister wishes not to petition for probate (since house is still in descent's name) what else if anything can I do ?

I wish I had started when I was our age.        

Hindsight I wish this was stated in the purchase agreement, but foolishly didn't anticipate this being a problem. 

Wish I owned the multi-family house I lived in!

I just wish they had told me and used me as their agent!

Congrats on having a plan in place post-graduation - I have said it many times before but I wish I would have started house hacking when I was your age!

I wish you the best, if you were my daughter I would be extremely nervous Dad, same goes if you boyfriend was my son.