If someone is uncomfortable with the idea of anyone using their ideas or art, then they’re better off not participating.
Release the low-res art online if you want to participate but worry about people printing it off.
the whole point of creative commons is that it’s not behind her back any more; the license explicitly gives everyone permission to do that
copyleft (or even more liberal MIT-style licensing) is totally scary but it means more people can create more interesting things without worrying about treading on any legal toes. there will always be dicks in the world and you are probably best off not worrying too much about what they do. if all they’re doing is reselling your art as-is, what’s stopping you from doing that yourself? and if they added their own spin to your work, well hey, you just helped someone else do a little bit of creative expression.
creative commons is for enriching culture as a whole, at the cost of letting your children go explore the world for better or worse
i might have to write a big ol’ serious post on copyright and copyleft now