Some optional items from a LTR lease now become requirement: you have to own the utility account, definitely have contractors to maintain yard, pest control, periodic soft wash the exterior, pool/hot tub (only speaking from FL, or any other property routine maintenance in other region). 

For these interest only products, they are generally only interest only for a short period of time, anywhere from 1 to 3 years is pretty typical. 

I would just wait and if I didn't get the new rent amount when rent is due I would let her know she has until the end of the grace period (if you have one) to make up the difference or she'll  incur a late fee.

The 60-month period ends on the date the home is sold.

OP the key behind wholesaling is to be able to resale while you are contract while your due license or financing period is running.  

The original business plan was to implement the strategic CapEx program slowly over a 3-year period and then market the building for sale.

Count me in when you're trialing your newbie consulting services!

This is true with how you structure your deal: pref, carry, fees and waterfall, projected return thresholds, hold periods, etc.Reputable sources: there are many mastermind groups out there.  

You might consider asking the owner to seller finance part of the deal and also stay on for a transition period to help show you the ropes.

It will lower your rate and help you cash flow a bit more, and if rates do come down after that period is up, then you can look at refinancing.