However, your investment in the house, officially called tax basis, did not go up.

Ignore seller finance for a second...Can you buy a house, put 20% down...yes.

She would be putting all the cash down for the property and I'm a contractor and would take care of all of the rehab work along with finding the house, dealing with real estate agent etc. how can we make it so that it would be 50-50 ownership of the property and all future profit? 

Local Investment StrategiesHouse Hacking: Given the affordable entry prices, Albuquerque can be a great place to start house hacking, especially near the university areas.BRRRR: For those familiar with the Buy, Rehab, Rent, Refinance, Repeat method, there are opportunities in Albuquerque to purchase under-valued properties, especially in areas undergoing gentrification.Airbnb/Short Term Rentals: As previously mentioned, the city's rich cultural appeal can make certain properties lucrative for short-term rentals.

 I am a relatively new house flipper. 

Having a long-term rental while living abroad is do-able.Flipping houses while abroad, in my opinion, more difficult, especially if its your first go around with real estate.I would recommend taking a flight and staying in the area for a week and inspect the neighborhoods and make connections.You can reach out to @Elenis Camargo who has a PM company in Jacksonville.Best of luck though.

At 19, house hacking is the best option if you have the downpayment and closing costs set aside.

Here are the numbers:IncomeTotalPartner ContributionsManaging Partners Debt$0.00Partners Deposits$987,459.99Total Contributions$987,459.99Operating IncomeAirbnb Income$50,186.50Square Income (Vehicles or add-ons)$6,741.04Total Operating Income$56,927.54Total Income$1,044,387.53ExpensesPurchase of propertyCost of House-680,000.00Closing Costs-$26,744.44Total Cost of Purchase-706,744.44Set Up ExpensesHouse Improvements & Care taker home addition-116017.03Adding Tiny House-52130.83Furnishings-68403.65Vehicles-43150Set Up Costs and Advertising-2339.53Total Cost of Set Up-282,041.04Operating expensesCare Takers-14535.9Additional Cleaners-1505Cleaning Supplies-2670House Supplies-1340Landscaping-4230.66Utilities (Power & Water)-8204Internet-315Pest control/fumigacion -120Pool cleaning/maintenance-2220Vehicle Gas-552.3Vehicle Maintenance and Repairs-6625.01Welcome Food for Guests-115Property Repairs-4999.64Bank Fees-1208.06Accounting Fees-1085Insurance-955.74Other Expenses-1071.2Total Operating Costs -$51,752.51Total Expenses-$1,040,537.99Net Income$3,849.54Net Operating Income$5,175.03Now 5k for an investment of 970k is not a good investment.  

I'd love to hear others' opinions on this but I am a fan of making the house as attractive as you can to a potential buyer, even if that adds cost. 

My cousin is using one and likes it.Cell service is weak at our cabin PF so it would not work there.Might be good for a smaller house in an urban area with good cell service.