Best way to transfer property ownership during break-up

[Blake Piedrahita]

Hello, my long term girlfriend and I are breaking up (for reasons I don't want to get into here).  We currently live in a house-hack duplex, but we purchased it under her name so we could take advantage of a first time homebuyer program.  

Now that we are splitting up, she has no desire to continue living in the home and plans on selling.  I put in most of the work and manage the day to day of the AirBNB, and very much want to continue living in this house.  My question, is what is the best way to purchase this home from my soon to be ex-girlfriend?  It has appreciated by about $50k since purchasing and I'm happy to pay her full market value, but I'm wanting to do so in a way that minimizes transaction costs.  She has a sub 3% rate on the mortgage too, so if there is any way to transfer ownership to myself and keep that rate it would be ideal, but not 100% necessary, as I could afford the mortgage on a 5% interest rate.  

Any help is much appreciated, and happy to add more detail if needed.