Widget horizontal divider line

I installed a Leaf child theme and I think that’s when the squiggly horizontal rule next to widget titles disappeared. I can’t figure out how to get them back, even though I’ve re-uploaded original CSS and widget.php files.

The image appears if I reactivate the original Leaf theme.

Please help if you can.

My site is http://www.savesouthwestmuseum.com/

thanks

Tanya