Similar green energy investments could be considered if you can make the numbers work (credits on some types of low income housing can be north of 50%).Depending on how long these properties have been held, they could consider implementing cost segregation studies via a change in accounting method to accelerate some depreciation.The operating proceeds could be re-deployed into new properties where cost segregation is an option to accelerate depreciation to offset proceeds.If the properties are low basis and we are not maximizing the 199A deduction, maybe considering an S-Corp structure for management to be able to participate in retirement plans and also generate wages to use as a 199A base. 

Quote from @Andrew R.

My method as well. 

If there's an alternative method that has worked for you, please share. 

We were initially looking to flip homes, which would potentially bring higher immediate cash returns for her enjoyment in her later years, however I’ve been researching the brrrr method as well to generate cash flow without the stress that flip process may cause her.

Using the next ten years and the snowball method to pay them off.

@Shai Galapo two methods I would suggest here.  

If you want to gather emails and do some email marketing, there's a new company that many hosts have been pretty happy with....Go STR MarketingI will check into this company. i don't think this will be a substitute for StayFI as you still need a better method of capturing data beyond just the contact date you get from your PMS.

Not sure if this is the most recent post on land flipping,  but I came across another ed platform -  The Land Method and Land Riches Blueprint. 

Or would be worth pursuing a R-62 Minor Home Improvement License as an extra precaution?