We originally had the idea of me buying the property and having the deed solely in my name, with her using her underwriting-friendly financials as a cosigner/co-borrower.

The 'better' alternative is as @andy points out  to borrow from an independent party, with recorded security interest, proof of loan term compliance... all in an arm's length transaction.

You guys could borrow a hard money loan to cover the purchase and rehab and one renovated refi out. 

Right to Redemption means "The legal right of any mortgagor or borrower who owns real estate to reclaim his or her property.

When you apply for the mortgage the application will ask "is any part of the down payment borrowed". 

I used a construction loan for $84k and borrowed $20k from a good friend to fund the down payment on the loan.Over the next 3 months, with the help of my parents and my father-in-law we rehabbed the home.  

In the meantime, you didn't get paid, so you might want to get payment from your borrower.

In other words would you drop the price to 100k or 103500 since they would only be borrowing 100?

This is a great way to get your feet wet and one of the few ways you can get into multifamily rentals without 20+% down.Now is a good time to go in and talk to a loan officer at whatever bank you'd prefer to borrow from (a lot of folks will go where they keep their savings/checking).It would also help to have that discussion before you start shopping so you know how much the bank can/will qualify you for.

That includes Realtors or operators.I've wholesaled more than most, it's the best way to get a new borrower into a poorly performing arrangement, it's a cure for pre-foreclosure issues and I've flipped contracts under a variety of circumstances.