Thank you Kathryn, I try to avoid using plug-ins so I tried hard-coding into my child theme (following these instructions from here https://docs.woothemes.com/document/add-a-custom-logo) with no success.
I ended up resorting to a plug-in, and had success using one called “Easy Logo” (https://www.ads-software.com/plugins/easylogo/). (I couldn’t use Jetpack because the site is not currently publicly accessible.) The “Easy Logo” plugin did require one line of code in my header.php file, but I don’t mind.
Thanks again, hopefully this may help someone else if they encounter the same problem.