Good point NCB, My mother has it. It is most common in people who carry excess weight, although you don't have to be heavy in order to have it. Now she is doing much better- her blood pressure went down and she feels so much better.
Maybe the next time your wife talks about her sleep and not feeling rested (maybe try to bring it up without being pushy) you could say that you recently read something about it, or a friend of yours mentioned it to you, and that perhaps she should consider having that checked. Leave it as that- plant the seed in her mind and see if she runs with it on her own. She may be rationalizing right now that her lack of energy is due to her weight......
