You say your husband has been self employed. Is his business still viable? If so, can you run it or perhaps sell it if it has any value?
I was going to chime in with the same question/suggestion.
My wife and I have owned our own small business for about sixteen years now. She's been my business partner from the very start, and knows just about everything that I do about running this thing.
I've often told her that if anything were to ever happen to me, that I want her to step up to the task and keep the business going at all costs. It's been her career since her mid-twenties, and after being a stay-at-home mom for so long, it's really the only professional job she knows.
If she were to try to jump into the job market at this late date, she'd wind up working as a tax preparer or book keeper - neither of which can pay her as well as running her own business.