I finally figured out that Invite only asks whether you want to start your own blog. In Chapter 12 of my Teach Yourself Visually WordPress book, I learned how to add a user to my blog. And I just discovered this morning (on sandboxesrus) that this functionality is different (and less robust) on .com than it is on .org. So I have added my wife as an editor to this blog (because I can) and as a contributor to sandboxesrus so we can get to the bottom (or to the top, to mix my metaphors) of the learning curve. Once I have this figured out, we can finally get Healing Pathways back on the rails.
Update [1 Mar 2015]. Reviewing this post today I noticed that the link for the book no longer works. Reviewing the book, I also noticed that it is rather dated. So here is an image of the book I mentioned (the first edition) and a link to the current version of the book (the third edition). See my blog post for today [1 Mar 2015] for the book I am currently using to refresh my knowledge of WordPress.