Easiest solution may be to just install an additional layer of soundblocking drywall on the existing 1st floor ceiling, but don't know how effective it will be

The lady who stayed, love the house and want to start a new lease and have new housemates as she can’t pay the whole rent (she paid half the rent end of June).

It is actually for sale the owners had the property for almost half a century I am in the middle of finding everyone needed for the project before I fill out the application for private money.

I'd say close to half don't even ask me what updates I did to the property unless I volunteer the info. 

The rental seems the easiest way.

The only smooth FSBO transaction is one where the buyers agent does the work for both sides for only half of the usual pay.  

That imo is by far the easiest and cheapest way to get a portfolio.

Otherwise if she's not okay with you keeping some of the deposit and you can't get a meter reading, then take the last year's worth of readings and take the highest bill and charge her half of that. 

Here in Kitchener with a duplex while living in it, it appears I will have to foot about half of the expenses.

They charge half month rent.