Adding a line to the footer

Hello,

I purchased your theme and have put together a web site with very little wordpress experience. I have found myself needing to add an image to the footer that goes across the whole page (a list of icons for credit cards accepted) as well as some text on the left and right. I want to edit the footer to just go ahead and include the graphic and use the existing footer layouts for the rest.

How do I edit the footer in a child theme to just add that image? I’m sure it’s easy. If you could explain it or refer me to the proper documentation (that I’ve searched for but can’t seem to find) I would really appreciate it.