Not that long ago it wasn't uncommon to have network sites: one home page to link you to many different smaller pages. Most of the ones I knew were for hobbies or fansites, but the system could easily be tweaked. You could have a series of 10 or 12 blogs, linked from a common index page, each posting whatever the author felt like. It wouldn't have to be a magazine, exactly, let alone share the same site layout.
Mariko wants to create a modern version of what she had at Gunsei, but it still isn't clear what for. Although I'm not sure she really needs to write 'for' anything: it really would be enough if she just kept writing online and sharing on social media... and she could easily tell other seniors how to do the same, once she's learned. I don't know how this is going to get resolved.
(Whenever I see those convenient wiki-based fanpages, optimized for mobile viewing, I think about how many fansites were lost to time as people gradually lost their places to belong. Why edit and code a website that's only optimized for viewing on a certain size monitor when you could just put information into a wiki that everyone can use? The Internet is a constantly-changing place. This young girl may have used it her whole life, but staying ahead of the game isn't that easy...)