OOPS! Still have a problem. When I switch to the Child Theme, the "Icy" logo comes back, overlapping the Site Title. I guess this has to do with the fact that once you switch to a child theme from Icy, the option to pick your own logo disappears (in Customize), so their logo comes back. What can be done about that?
Addendum: Ok, I added this to css, to hide their logo:
#site-title a {display:none !important;}
...and created a new div in the script, site-title1, which I then styled in css. It seems to work, but is this the best way?