How to tell if a Child Theme is installed and how to install, if not

I have a question on the Child Theme and working with Local. I am working on Local because I already have a simple website installed on the domain name that I will install my completed Flatsome Themed website. I don’t remember when I set up Local if I selected the child theme option (I am thinking for the future when my Flatsome Theme site goes live). Where would I find this information about the child theme and if it is active? If I need to make it active, how do I do that retroactively now that I started to build in Flatsome using Local?