After our certain disagreements on the thread about lap children (yet I think we catually mostly agreed without realising) I feel compelled to respond to you here as I do feel for your wife.
Firstly, I know most major airlines here in Europe offer courses against the fear of flying which usually include a real flight, but I don't know the availability of this in the US.
I feel for her as I went through about 4 years of total terror while flying after a couple of incidents (one involving my parents and one I was involved in).As a lover of aviation, before feeling this fear I never totally understood what people felt when afraid of flying until I suffered it, and I can tell you it is one of the worst experiences anybody can have.
Get your wife to talk to her GP
or even a psychologist. Fear of flying is actually often a form of claustophobia or is simply where an underlying problem with anxiety arises (as the passenger is forced into it and has no way out). I think this was my case, without really realising I ahd an anxiety problem, the incidents on the flights and the subsequent fear of flying brought an underlying panic/anxiety problem to head, which has since been 98% successfully treated (regarding flying, I started to realise I wasn't actually really afraid of flying which is what I thought, but I ws actually claustophobic and afraid of having some sort of panic attack on a plane). I went to a psychologist a few times, and was prescribed Xanax which worked wonders. But remember, drugs should only be prescribed under medical advice as perhaps your wife's fear is different.
Feel free to send me a private message for further info.
One thing which may make her feel good, I remember once watching a TV
programme on the fear of flying while living in Spain with a large table of medical and aviation experts, and I clearly remember them saying that people with a fear of flying are usually more intelligent than people who don't have a fear (this obviously excludes professionals within the business, such as pilots!). So just tell your lady she's too intelligent.
But seriously, feel free to contact me if I can be of any further help to you/her.