I just upgraded to 3.1, and it seems I can only edit a theme (such as Twenty Ten) to apply to all sites that use that theme. I edited it just to see how it would work (no child theme yet) and it applied the changed theme to all sites I have that currently use Twenty Ten. Is there a way to edit and apply separate child themes to other sites that also use Twenty Ten in my network?
I went to Network Admin > Themes > Editor if that helps.
I'm assuming there's a way to do it, but so far haven't found a way to do this.