If for some reason you can't qualify, Your only option isn't 203k if you can't qualify there are other conventional options that have resemblances.

Each of the four of us, my partners and myself, came from different places in life…none of which resembled financial success and none of us had put anything in place that would leave our families in a stronger financial position when we pass.

Start with something that resembles what she's use to, less work, less hands-on involvement, yet comes close to what she's seeing in her stocks on a monthly basis.Lastly I would ask her to do a mock REI portfolio with you, find a property online, if needed do a mock rehab on it, rent it out at conservative rental rates etc... maybe this will let her see that you know what you're doing without initially taking the investment risk, just be conservative on this because if your Mock portfolio fails it's over getting her to say yes. 

I don't expect the next down cycle to resemble that at all. 

Worth their weight in gold...don't go it alone if you plan on having any resemblance of a real estate business. 

  ( that ship sailed on the west coast about 4 to 5 years ago) that until these things happen we are not in a REAL estate created recession downturn what ever you want to call it.what I see is stablization IE run away appreciation has calmed.. but I still see investors who need to make highest and best and look at your situation 8 months to find  ( Granted a Better than average buy).. we are still some time away from anything resembling a full blown real estate recession etc..

If you put a payment plan in writing and include interest on their money, it starts to resemble an actual investment. 

You can struggle through life using spreadsheets, but as soon as your hobby becomes anything resembling a business, or you can't remember everything in your head, double entry bookkeeping is the world-wide standard. 

Obviously look at solds in the area that mostly closely resemble the flip once its down but any other tricks of the trade you do to reign it in further and become more accurate?  

If you want anything resembling Fannie/Freddie terms (30YF etc), it's 25% down on a 2-4 unit non owner occupied investment property.