I have no concerns about her integrity and ability to pay, I am concerned though about the financials and wonder if I should move forward.  

I have no prior experience in Real Estate but became interested upon seeing the financial freedom some have had with it.

Typically you can request T12 financials, some will also provide the past 2 or 3 years.

Does anyone have an recommendations for banks/financial institutions that we can house our Solo 401k Trust with?

@Kate Pierse last year Civic Financial accepted a BPO for a flip we bought.

At what age did you start investing in real estate and at what age did you become financially free?

Would you be willing to share a broad generalization of the financials?

It is important to be able to analyze the trailing 12 month financial statement of a property and take a deeper look at the loss to lease by examining the rent roll.Ideally, you are lucky enough to have an excel version of the rent roll provided to you by the broker or the owner you are interacting with on your potential acquisition (or.. if you or someone you know is developing a character recognition software that is able to read a PDF version of a rent roll and convert it to a nice, clean excel version please let me know!).

In preparation for this move we have taken a financial audit of our circumstances and see that our 401k (I have the only account now, just shy of $100k @ 40 and my wife has just begun to contribute to her own this year at 33) will not get us where we want to be in 25-30 years.

Put together your Financial  & Dad's Financials and start talking to Lenders.