In addition to that, if you are paying for utilities or services that are not individually metered, you can pass those on to the resident as well, pro rata.

Of the 100's of MF syndications I have seen, I recall only one or two that did not share the depreciation pro rata. 

You can have only one general purpose loan and one residential loan at a time.You must wait 60 days from the time a loan is repaid in full until you are eligible to apply for another loan of the same type.The TSP will deduct a $50 fee from the proceeds of each loan issued.Your loan will be disbursed pro rata (i.e., proportionately) from any traditional and Roth balances in your account.For complete rules, and to understand the potential impact of your loan on your retirement income, read the TSP booklet Loans.

You simply create an LLC and split ownership pro rata. 

so currently,GP- 5% equity - 30% profitsLP - 95% equity - 70% profitsproposedGP - 5% equity - 30% profitsGP - 35% equity (raised through additional investors by GP) - 26% profit (if that previous 70% is split pro-rata)LP - 60% equity - 44% profit (if that previous 70% is split pro-rata)

For your investment, you will earn quarterly or monthly distributions, as well as your pro rata share on any capital event.

If there was a trust involved, it could have a non-pro-rata distribution clause that allows some siblings to receive different assets, so long as everyone receives an equal FMV of assets. 

I feel it might be better instead of borrowing the money from them to let them partner up and share in profits pro rata while we also take a "management fee %" off the top of the profits.

If the land contract fails and she takes the house back, then I expect that a pro-rata of the loss would be picked back up as income.Any insight would be appreciated from anyone who has encountered this situation.

You are certainly entitled to keep the pro rata portion between them leaving and you re renting the place as well as administrative costs, cleaning, etc.