LaserJet, is she finding the kinds of jobs she wants? She may have been out of the job market too long, as mentioned above. Or finding very negative attitudes in the field she is looking in. Not to mention ageism.
General comments:
I know a lot of older people, coming out of divorce or widowhood, who actually do cohabitation agreements instead of marrying. In these cases there are usually significant assets and/or children from the previous marriage. Of course they are not usually planning a new batch of children together. However, it certainly clarifies the financial aspect.
A spendy spouse can wreak a family's finances whether they are earning income or managing the home. It takes 2 financially sensible people to have the finances work well.
If a SAHS is a good home-maker, costs will go down considerably, but even in a both members of the couple working household the expenses don't have to be horrible - they just shouldn't have 100 hour/week jobs that suck their energy. There is a reason working-outside-the-home women joke about needing a "wife" - what they also would appreciate is someone doing some of the heavy lifting at home. They usually end up working 2 jobs, the one at work and the one at home.
If OP's future wife works hard at managing the home and then finds that all her hard work (and it is hard work, and she is not accumulating SS/IRA, etc. for her retirement) is not appreciated, then the divorce he doesn't want may well hit him. People in a good marriage are a team in all aspects of their lives. Including the finances.