Trying to figure out a fair and equitable deal here

[Aaron S.]

Background: In March I bought my first house hack as a single, unmarried man with a VA loan. While I paid all closing costs and a 15% down payment*, my girlfriend paid $5,000 of the down payment in exchange for equity in the house. She mostly did this as a favor to me because I was not expecting the VA appraisal to come up short and I struggled to take out down payment funds. Ok, so far so good.

We moved in together to the new house and split the PITI and utilities 50/50. We also have two tenants who live on the property and we split the rental income 50/50 as well. My girlfriend also owns another rental property that is 100% just hers. I moved in with her there in December 2020 and she was house hacking with a roommate and then Airbnb. She shared the rental income with me 55/45.** We also had a rental agreement for me living in her house and currently have a rental agreement for her living in my house.

90% of the furniture in the house belonged to my girlfriend before we moved in together. The 2 rooms we rent are fully furnished with her bedroom furniture. The only furniture in the house that was mine before we got together is our master bedroom furniture. When I bought the house that we currently live in, my girlfriend moved all of her furniture into it and rented out her house unfurnished. It cash flows a nice $500/mo, 100% to her of course.

The issue: My girlfriend wants to buy into 50% of my house and get her name put onto the title. I am comfortable with that and agreed, however there is an issue with her career. She has a medical problem and is an active duty military officer. She will have a medical review board to decide if A) She will stay in the military and be retrained into another career field, which would almost certainly force her to relocate somewhere else in the world, or B) she will be allowed to separate with disability pay/medical retirement. She has a great degree from a very prestigious university and will likely be able to find civilian work (remotely) without much problem.

The issue is that because we do not know what will happen to her, and we are both very against trying to maintain a long-distance relationship with possibly no end in sight (ie, the military can move her anywhere and is not obligated to ever return her to her current, local base of assignment), we are hesitant to continue with her buying into my house. If she is forced to relocate, as of now our plan is to end our romantic relationship due to the logistical challenges it would present. Supplemental information is that I have a child from a prior marriage that lives here in town with their mother and I do not want to relocate away from them for at least a few years as they grow up. 

Because my girlfriend is, at this time, only owning a $5,000 share in the house, I as the homeowner have been solo paying for most of the many house-related things that a landlord/homeowner should: buying a refrigerator, window treatments, furnishings like rugs and carpets, shelves being installed, repairs etc. Our thinking currently is that if she is able to exit the military and remain in our relationship, that she would retro-pay 50% of those costs (including closing costs) to me as a 50/50 co-owner and be put on the title, along with a legal agreement giving her 50% equity in the house. As if she went in 50/50 on the deal with me from the very beginning.

If she is forced to move with the military and we end our romantic relationship, then she could either keep her $5,000 stake in the house or I could pay her that money back. I am not sure what we would do with all of the furniture because again, she owned pretty much everything except the master bedroom furniture prior to us getting together. If we broke up and she (rightfully) took her furniture with her as she moved out, that would obviously disrupt our tenants because they are renting fully furnished rooms (with her furniture). Conservative estimates for me is that breaking up and her leaving with all of her furniture would cost me $10,000 to replace the goods and $5,000 to pay her back for her part of the down payment.

My question is, what would be the most fair way to do either option A or B, depending on what happens with her career/our relationship? What am I missing here?

Thank you!

I'd like to get out ahead of some predicted statements that I am not looking to argue or debate:

"You should never buy a house with someone you are not married to." 

"If she did not know what her situation would be then you should not have moved in together/combined living situation"

"This is a bad idea."

*This was to make up the difference between the VA appraisal and the sale price.

** This was because all of the furniture and the property belong to her alone, but I did all of the turning over service/cleaning/preparation for ABNB guests. She was generous enough to profit-share with me at all, so now I do the same with her in my house with my tenants. Except it's 50/50 because she still owns the furniture that the tenants use.