How to get a beautiful publish backend for client?

Hello,
I currently have a site for a client (which is my sister). She is not tech-ish and I need a polished interface to edit and publish content, for instance like a Wordpress backend. That could also be a local client.

The site is on a shared hosting, on which I can host a PHP bundle.

What would you recommend as a solution for that kind of issue?
Thanks by advance!

I have used https://forestry.io/ for a couple of clients and the works nicely. You link the forestry account to the git repo of the site. Easiest is to use GirHub and GitHub pages.