It appears that it's a HTTPS issue, as per the mixed content error in the console.
If you want to embed on a HTTPS site, you will need to set the forum to https.
First you need to set a custom domain for your forum, with the same base domain as the site you're embedding on. For example, forum.jacobanddebbieacro.com. You'll need to set a CNAME record that points to n8.nabble.com.
more information:
http://jacobanddebbieacro.89018.n8.nabble.com/help/DNSConfiguration.jtpOnce you've done that, I'll be able to enable https on our end.