On Friday, we're planning to meet up with Connie's family at their home in Penn Valley, about 15 minutes west of Grass Valley on Hwy20. Connie's dad and 4 of his kids (Connie's step-siblings) are coming, too. We won't be able to leave their home until all of their kids get home from school (probably around 3pm). From there, it's about 2 hours to the trailhead, and 45-60 minutes to the campsite.
So, I don't know where to meet if you're leaving Friday. If you don't mind waiting/caravanning from Penn Valley, you can meet us there.
Otherwise, I'm not sure when/where to rendezvous.
This link highlights the route we'll take from their house to the campground.