I'm not trying to make a long-distance diagnosis, but what you describe makes me think that your wife likely is having problems with depression, and I think you need to deal with the possibility. Symptoms include irritability and disturbed sleep schedules. Speaking for myself, the endless time spent on trivial activities and the shirking of responsibilities sound awfully familiar.
Giving her a talking-to, as some of the other answers suggest, isn't going to work if she'd depressed. What you're going to accomplish in that case is to make her feel guiltier and more stressed and generally worse. Try to figure out what's going on with her and then talk about responsibilities.
There are online tests for depression, but the best thing probably would be to get her to a doctor for screening. (Given your description of finances, you've either got good health insurance or can pay for good care.)
It may take a long time to get out of depression (it did for me) and it's frustrating to live with a depressed person (ask my wife), but knowing more or less what's wrong may help, and if she starts making progress things will get better.