Spent way too long on this...

I had already added the User Tags plugin and it was working great for Administrators.

BUT, I wanted my Mom (only a User) to be able to add new tags, while updating comments for all of our family pictures.

It appears that if a photo doesn't already have at least one tag, then the only way to do that is via the Edit button, which I never figured out how to have that show up for only a User.

But then I noticed that a User can add tags if one tag was already created.

So I used the batch manager and adding a single tag called "All".  Now it appears to work as I wanted.
Her instructions will be to remove the All tag when adding a new tag.  This should work out just fine.

Thanks for the great software!
  Paul