Footer Widgets for 'Twentytwelve' not showing correctly

I wanted to add 3-column footer widgets to my ‘Twenty twelve’ theme, and found free help offered at Zeak’s Blog. Zeak provided the code, and a template for a child theme. A number of people have successfully installed these widgets on their sites, so I was encouraged to try myself. After installing the child theme directory in my host’s theme directory (alongside the ‘Twenty twelve’ directory), I modified and added ‘footer.php’, ‘functions.php’, and ‘style.css’ files to the child theme directory. The footer widgets appeared on my site. I created 3 custom menus filled with parts of the horizontal site navigation bar. Unfortunately, all three menus are stacking up on the right-hand side of the footer (see url: https://gardenofyoga.net/wordpress I can’t figure out how to place these menus in their respective left-, center-, and right-side footer widgets. I’ve attached the code from each of the child theme files for anyone to examine and let me know where I might have gone wrong.

Pastebin url for functions.php: https://pastebin.com/ZFT6kPgM
Pastebin url for footer.php: https://pastebin.com/58gt4PTZ
Pastebin url for style.css: https://pastebin.com/dfiqrcmD