I am re-working my way through Wicked Wordpress Themes Book, and am struggling to build my own Widget, (end of chapter 6)

After working through the chapter and the code without success, I eventually just pasted the downloaded finished code page from the code archive for author-data.php into my widgets folder in my thematic child theme, but the widget doesn't show up on my interface.

I first visited this a year or so ago (earlier version of wordpress) and then went on to other things, and I'm sure I got it working then.