Resolved Question: What is a good formula for splitting profits on a rental property investment?

My mother and her on again-off again boyfriend want to rent a house from me. They will pay all utilites and fix up the house in turn for no rent. The house right now is a wreck, but I planned on getting a home equity loan and fixing it up then renting to make a small profit.
I am very scared to rent to my mother and her BF because of their unstable relationship and my mother's tempramental moods.
This would be a good situation for me because I live out of state and they could take care of the house until I can get to it (about 1 year). But then it could be bad if they split up because he is going to do all the repairs and she can't afford it on her own.
I know what I would do on a business level, which would be "No", but what do you think? There is no mortgage on the house.
The only bills are the gas, electric, water and tax bill.
I cannot live there right now because my hubby is in the military and we are stationed put of state. We DO plan on living there in approx. 3 years. We will go back in 1 year to do all of the repairs and hopefully rent it out for 2 years. I would have a lease contract written by my attorney. I would have it include:

*All bills and expenses are to be paid my tenant.
*$6000 in repairs are to be made by the end of the lease agreement.
* Property is to be maintained by the tenants.
*Anything else I can think of. Thank you all so much for the answers. I just wanted to make sure that I am doing the right thing.

Resolved Question: What is a good formula for splitting profits on a rental property investment?

I am involved in a 3-way investment on a rental property and we are being forced to sell because of a DOT project. Our profit on this property will be approximately $75,000 and we need to figure out how to split this up. Being close family members, we weren't too concerned about figuring this out we bought the property.

I would really appreciate any suggestions from real estate investors experienced with partnership investments like this.

Here are the figures for the capital and work/mangement invested by each party.

Investor #1:
Invested $150, 000 by taking out a regular home loan.
Lived at the property and payed "rent".
Did 85% of the maintenance, improvements and rental property management.

Investor #2:
Invested $75,000 from a home equity line of credit.
Did 0% of the maintenance, improvements and rental property management.

Investor #3:
Invested $25,000 from a home equity line of credit.
Did 15% of the maintenance, improvements and rental property management.

Thank you!

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