Read "Passionate Marriage" by David Schnarch and check out the web site at Murray Bowen Center for some good info on marriage and life. My 5 second analysis of this is that she feels that her emotional needs are not being/will not be met.
I think it is a good thing for kids to see their parents setting reasonable goals, making rational plans and then working through the unforseen things. Prior planning can reduce, but not eliminate, the unforseen. There's a lot of information on the web and other people are doing this. This isn't like mountain climbing or some singular activity.