Creating a Child Theme after Customizing the site

I’m embarrassed to say that although I’ve been a web developer for 20 years, I’m relatively new to WordPress. I’ve built several WordPress sites already, but being somewhat new, I have only recently learned about child themes, why I need them, and how to create them.

So, I had started a new site for a client months before I knew all of this. I’ve created and customized the site using Enfold 2.8.1, and now I have gone back and created a child theme, so that I can update Enfold to the newest version and make sure my customizations are not changed or lost.
I think I’ve done it correctly, but I had to make screenshots of all my options, settings, etc… so that I could reset them in my child theme. I’ve done that now and the site looks okay, but I’m supposed to show my boss, and our client tomorrow, how the site works, so we’re at the end of a long 8 months of working on this site, and I need to make sure there are no problems or surprises. So, I’m going to wait until late at night, as I am tonight, to work on the site. I’d like to update the theme to the newest version, but I was hoping you might be willing to take a look at the site first, before I do that, and let me know if you think anything will break or change if I update the parent theme. Since I haven’t done this before, I’m worried.
Is there any way you could help me this one time to make sure I don’t break anything? It’s really the timing that’s so bad, with us about to take the site live and the client giving us a final approval today.

Can you tell me what things to look for, or any information I would need to know to update the theme without issues?

I would be so grateful.
Thank you.