Id like to get it under contract (with a partner), redo some of the units, fill the three vacancies and buy it for myself (from a partnership I am considering with another investor) in a year or two.  

@Asim Alam higher average rents (could be easily 2x-4x more depending on property and location based on some properties I've analyzed with an AirBnB in mind), but also higher vacancy and turnover costs (although some turnover costs are mitigated by an added on cleaning fee).

Now that life and financial situations have changed, she sees the house as an albatross and I want to help her find a way out of it.With that said, it seems to me that any scenario involving me inheriting the house as part of an estate would mean a high likelihood that I would be covering part (or all) of any mortgage shortfall, such as low rent or vacancies, as well as other expenses at some point in the future, without the house being in my name.  

Any vacancy is better than a bad tenant. 

.- Make sure you figure out some more specific expense numbers, for example: Mortgage Payment, Insurance, Taxes, Maintenance, Vacancy, Capex. - Don't use Zillow for any numbers, especially the Zestimate for rent or sell price.

HOA Fees $0.00   Lawn/Snow $0.00   Vacancy $150.40 8% Repairs $100.00   CapEx $131.60 7% Property Management $0.00   Mortgage $381.93   Total Monthly Operating Expenses $1,469.93  

Currently the house is close to our college and has an extremely low level of vacancy due to this.  

Assuming you work with the tenant and give plenty of advance notice there is no reason you should have any vacancy.

If he's long term AND has a low rate of turnovers and vacancies, this *might* just trump all other considerations - - aka you're getting added value there.

i dont see capX. vacancy, the annual repair number seems quite low thats only $71/year per unit, as does grass and snow you have only $55.50/mo. i doubt that covers one snowfall or grass cutting per month , you will also have garbage service you need to pay for, and if the city requires you to pay for Fire inspections, or licensing being commercial they can, as well as sprinkler system and fire extinguisher contracts, common area cleaning and maintenance,  and Management. im probably missing something here yet. so rents average $500/mo fully occupied?