What are gross rents (including your contribution)?

You are smart to step in to help advise but that is the best you can do unless you both are contributing to your household expenses and the difference she has to pay towards the condo will create shortage in your household. 

@Timothy Young since I have no capital do you have any thoughts on what I can do to contribute?

I contribute $1k to my IRA. 

Seller contributes property, buyer/flipper contributes work and rehab costs.

As an owner-only business retirement plan, the Solo 401(k) has higher contribution limits, allowing you to build your savings on the front end as well as providing investment flexibility. 

Craig,It sounds to me like you have a variety of options here, but for the sake of contributing to your line of thought, I will focus my reply on options 2 and 3.

I think that contributes to the fact that my DIA are very low.

And my guess is that you and the entity would have you then contribute the 5% you retain into an entity like an LLC in exchange for a 5% membership interest in the LLC. 

If you use a HELOC, you can take the cashflow from your investment property and use it as you please--including contributions to your 401(k).