My wife does has done a bit of cake making over the years, including some wedding cakes. She is pretty good at it. A few years ago I got her an airbrush for decorating her cakes and it has increased her decorating options, to include using some some stencils I made for her.
She was hesitant at first, but quickly got the feel of it.
So if your wife is like my wife, then buy two - one for her and one for you. The family that airbrushes together, stays together