I recommend "strewing." That's where you pick topics you think your kid will like, raid the library, and leave things lying around for your kid to discover for herself.
I realize that still requires a time investment, but hopefully it will pay off in self-directed learning. I find that a one hour blitz at the library, without the kid along, can yield enough to keep us going for . . . well, honestly, only for about three days, but my kid is younger and we read shorter books!
Have you considered getting a spare computer (see if you can score a decent used one), putting on some heavy site-blocking software, bookmarking a few educational sites, and turning her loose on it for an hour or so at a time?
And finally, I'm sure this has occurred to you, and I know each family has its own dynamics, but if hubby is dropping down to 80% time, can't he pick up a bit of the afterschooling?
