I need the Blog to only show up for logged in members
How do I add the blog into the logged in menu but keep it hidden from public view?
Your question is not related to wpForo Forum Plugin but WordPress Blog, We provide here wpForo Plugin Support.
If you have any question related to WordPress and not wpForo Please ask them at WordPress Support: https://wordpress.com/support/
About your question here is a Topic about what you were looking: https://www.wpbeginner.com/beginners-guide/how-to-make-your-wordpress-blog-completely-private/
Of course my question is related to wp-Foro. Why would it not be possible to have the blog be only used for forum members and appear in the logged in menu?
wpForo Doesn't control the menus, You can add the Blog Menu Link wherever you want, but wpForo cannot make it visible when the User is Logged in and hidden when the User is not logged in.