Many people utilize LLCs for many different ventures because they do not want to go through the hassle of opening another LLC.

Here's some online software options that you commonly see recommended on BiggerPockets.

This is a straightforward and common approach.However, make sure to document the change in the lease renewal or addendum, specifying the new security deposit amount.

BUT, get a solid quote on utilities.

I have heard that it is common practice that private money lenders collect a monthly fee thru various methods, I'm trying to determine what those methods are.   

There are a couple of others less commonly used. 

The catch is she is retired and won't have income except SS, thus I would be paying for everything...the HOA, repairs, utilities, insurance, etc.

On utilities, I bought a foreclosure in NJ and found out it was not attached to Town sewer and I actually had to extend the main line up to my property then put the lateral in and abandon an old cesspool.  

Utility improvements.

Just a follow up question, were you utilizing debt to invest, I have always been taught since a young age to try and not utilize debt (I come from a family of stock market investors, traditional business owners) where debt is not utilized as frequently which I obviously understand debt can be a very powerful tool and utilized in a great way its just something I want to avoid with my investments to an extent any suggestions for investing without debt or as little as possible.