Personally, we spent about a year and a half listening to podcasts, reading a bunch of REI books, and talking to experienced investors before we felt the time is right.

The person does pay her back and she did report the interest income. 

Challenges?

I personally want to use this strategy to lock in a lower interest rate on a rental property (being 20 years old with a small amount of credit history). 

If you have multiple people on the company, you ideally want the person with the highest credit score to have the most ownership percentages. 

Have you asked the person who trained you for direction? 

If you are worried about being over leveraged first look at your personal debts that are not producing income for you.Remember that when you are increasing equity in a property you are only reducing the risk of the lender.

This is a different person cleaned after cleaning people cleaned for a short-term rental. 

If it is a good deal then the right person will be willing to look at some private money options or even look to structure a partnership where they bring in the capital and lend-ability and you manage the deal for them.

Biggest thing is to make sure the agent and title company are competent in Seller Financing, I personally close my Seller Financing deals with a title company who has a real estate attorney on staff.