Ok, now it’s working.
As far as I could see the changes I’d made in other php files that inserted the sidebar.php via a function was no where to be found in the index and i’d only included the files I manually changed (header, footer, single, functions, styles and the folder \page-templates) in the child theme’s folder and thought that should be all I needed.
But turns out I needed the index.php file as well. I’m not entirely clear on the order of files being used (will look it up later).
