I have Preference Lite installed, and I read where there is a custom blank Child Theme for this in the Themes folder, so I can make modifications.
I have searched the entire theme folder in my directory, as well as in the Preference Lite folder down a level,and everywhere else, and have not been able to find this anywhere.
This is the site and wording where the author indicated this:
To help you get started, I've made a custom blank child theme for Preference Lite which is ready for you to make any changes to your theme. This will be found in the theme files in a folder named "child-theme".