I am a stay-at-home mom of an almost three-year-old and almost one-year-old.

If you're staying on the residential end of things, I would suggest contact your personal insurance carrier to start. 

I'm worried that during that because of that rehab period, my DC property could be considered my primary residence since I have a mortgage, and given the fact that I don't currently help pay my parents mortgage through rent and therefore can't validate me staying there.

If they stay until December, then you have collected $600 extra.

There is a double-wide trailer on the property as well which rents for 550 and is currently occupied, same tenant would like to stay when property is sold. 

I cant find anyone in my network, if they do have funds they rather stay in the market I just don't understand.

Essentially they become an investor in a larger property (multi-family, self storage, etc), receiving a preferred return every month with ZERO action required while still staying exposed to the real estate market.

I will stay in one of the smaller rooms and rent the rest out. 

Then I thought : "I don't have full control of the process here [can't force people to respond to me, I do have some time constraints, etc] but there is one thing I can control: staying active on BP!"

In the Denver area the trend is for the larger municipalities ie Denver and Aurora to limit STR to primary residences or stays or 30 days or longer.