It really just depend on the lifestyle that suits you best.  

I believe the formal name is an enhanced life estate deed which as Tom Gimer already pointed out does not pass title until the Grantor dies. 

As a previous tenant and now successful landlord, raising it 25%+ is pretty fxxcked up feelings on tenants that may have tightly budgeted for their lifestyle and capabilities.But if you do, please give them 60 or 90 days notice of any increase above 5% , it is the decent thing to do, and it is assimilating following the concept of many rent control cities.

These new site enhancements ROCK!!

I suppose these type of places exist in southern states like Fla , Tex , Ariz. etc; BUT it is NOT the LIFESTYLE my wife and I care to invest in .Honestly how would you Market such a Place either for sale or Buy and Hold Purposes ?

Thinking about developing a manufactured housing land lease lifestyle community?

I personally would probably try to locate an additional property but again you need to run the numbers for your area and do what best fits your end goals and lifestyle. 

Despite this, I have invested in various improvements to enhance her living conditions.

Think of it like compounded interest.Cut your spending, curb your life style and save every penny you can till you have your first down payment......and along the way make sure you are paying your parents a descent rent for their housing contribution to your future plans. 

First of all, most people nearing retirement age do not have enough money to sustain their current lifestyle when they do retire.