As part of this service, I will also install a child theme. 

“Why do you need a child theme?”

There are many reasons to use a WordPress Child Theme. The main ones are:
a) It is safer to do updates. A child theme inherits the parent theme’s styles, feature and templates, allowing for changes to be made to the design without modifying the parent theme files. As new versions of the parent theme are released, you can safely update it, without fear of losing any edits or modifications made via the child theme.
b) A child theme based on a powerful parent framework, allows the flexibility to extend the site, without the need to write a lot of code. This is a valuable time and money saver.