cimy and twenty thirteen header width not variable

I used Cimy header rotator with twenty thirteen at https://drgailpmyers.com/. The header width stays the same. Is there some way I can make the width variable?

I tried with and without the button “Adapt the container’s size to the window’s size (Requires browser page refresh) checked.”

I am not a programmer. I am an artist who can follow directions, so it is OK to be specific. Perhaps it doesn’t work with twenty thirteen and I should use another plugin, in which case, I am open to suggestions.

https://www.ads-software.com/plugins/cimy-header-image-rotator/