Many people prefer the security of a one-year lease in SF, particularly for rent control and eviction protection. 

A little bit of everything: refi’ing, private money, friends and family loans for down payments, seller financing, SBA loan, HELOCs, business LOCs, and most recently, cashing out the 401K for a grand slam deal. 

Feel free to private message me and I'll send you my details, website, etc.  

For example if your duplex (that you own) is worth $150K at most, given recent comps, then I would think it's fair to ask $225K (I assume builder will talk you down) and you do a private sale (avoid realtors costs) and perhaps settle at a $200K sales price. 

Every situation is unique and there is not a one size fits all approach to protecting your mother's financial security, but there are some options that each has an upside and a downside to.

All funds, coming and going, must pass the security checkpoint first, before moving through the door to the next location.1 - The loan money sits in that account until the borrower/REI has the investment lined up that will make the payments back to the lender. 

I would like to feel like I knew what I was getting into if I did use private or hard money.

Private lenders are better (IMO) because they offer more flexibility.

@Blake Edwards - I just keep my tenant's security deposits in a savings account. 

In any event make sure you follow the law regarding security deposits.