So the best solution is for the wife to get herself an email, and the husband to enter that on her account to invite her to join.
Then, once she has joined, he needs to add her to the Trusted Lists for the profiles he currently manages, and make her co-manager.
One of them then removes him from those Trusted Lists, leaving her as sole manager of all except his account, where she should be co-manager. Then he should follow the close account steps.
Done this way, none of the profiles for their living family members would be lost, and she would presumably be manager of his no-longer-a-member account.
Would that be correct?