I bought a house with my future wife (unmarried at the time of purchase) and my name is the only one on the mortgage. Subsequently we got married and I added her to th deed but not the mortgage. Currently going through a divorce and need to know if she has any rights to the house? I live in Virginia.

Her name is on the deed... that means she has rights to half its value just for that reason alone.. Specifically... half of any equity that may be in it since it still has a mortgage on it. Assuming there is any equity.

... I added her to th deed... need to know if she has any rights to the house? I live in Virginia.

Of course she does, as Smoothy has informed you.

Why would someone who owns half of something not have any rights to that something?

Yes, in some states she would even without you adding her, but the minute you added her to the deed, she now owns 1/2 of any equity in the home.