How do I become legal owner on GF house if she passes

[Ernest Rogers]

    My Girlfriend and I bought a house together, but its just in her name. If something were to happen to me, she is obviously covered. I need this same protection and peace of mind. If she were to pass, there is nothing that says the house is mine when its paid off. I've heard of Quit Claim Deeds , I don't know if that involves a Gift Tax, which I was told there isnt anything in South Carolina. 

    Details, Home is Mortgaged for $150,000, Value is higher around $200,000. Longs, South Carolina 29568 located in Horry County. I am waiting for a response form a local lawyer, but I don't want to get screwed for not knowing all available options. This isn't the best lawyer in the area, so I would like to go in with some info to ask and then make a decision.

     Any help, comments, insight would be greatly appreciated. We are not getting married at this time for the obvious responses of just get married and that will fix it.