Shallow DOF doesn't make a great photo. It's about composition, weight contrast, subject/content, among other things. A wide angle lens has a deeper DOF so more things will be in focus. A great photographer can take amazing photos without using shallow DOF. Sure shallow DOF is dramatic but when used as a crutch, is utterly cheesy.
Those photos your wife took have the wrong color temperature so they turned out too cool and pinkish.