Do not rely on it for legal advice.

If they are motivated at that time to redeem, they will also have to pay your legal fees for the ejectment.If you have a tax deed, you can just give some sort of deadline in the letter and file ejectment after the deadline expires.

Who gets to pull permits? 

"Best and easiest way to structure" brings up several points in my mind: deal structure + legal structure + tax implications (listed in the order in which I feel more versed, not necessarily their importance).

You dont put a mound system in until you have a house permit , they are sized to the dwelling 

The main issue that you'll run into with what you've proposed is that you cannot legally rent out 4 rooms separately in Philadelphia.

This is not legal advice- btw.

You may put in a ton of money and work just to find out that she has no legal claim over the property.If I were you I would keep in touch with her and get her through probate. 

I think were legal and within the scope of the law and NOT selling them today for more than they are worth.. is fine..your buyers if they are paying more than they are worth are not going to get financed once they get their appraisal.. and or in 2022 if the market has gone up its moot anyway you might really have sold for too cheap.. 

Is there any legal issue I would run into if I only kept scanned copies of leases electronically, or better yet, only had completely electronically generated and signed documents like real estate agents use?