The fact your wife has had few symptoms suggests beta+. Does she have a normal hemoglobin level? If she has been tested for her genetic mutation, I can research it to see if it's beta+ or beta zero if I know what the mutation is.
I don't think percentages factor into whether or not you carry a triplicated or quadruple mutation. It's based on whatever you received from the parent who carries it.
The problem with triplication is that far too much alpha globin is produced. When combined with the low beta globin, it creates a huge imbalance in globins and the alpha globin will form tetramers that are harmful and can create a beta intermedia like condition, where transfusions can even be necessary at times. This would be worse in beta zero, because the imbalance between alpha and beta globin is even higher.