It's a great concept, for sure. As [member="Zak Dymo"] covered, staying in sync can be difficult (it's useful to note that Zak was once 9 years old at the same time Jerek was 14, though they never interacted in the same threads, now Zak is 14).
I started doing something similar with Jerek in the republic, using NPCs for his group of friends. I got sidetracked and before I knew it, the GR had lost Ossus where the Jedi were based and everything went south. Sometimes Chaos will throw a wrench in your story, too, which makes planning on a long scale risky at best.
If you're really interested in this, I'd be down. Depends on what age you want to start at, and how that's going to progress. Will the group be mutually in sync (Harry Potter style) or are they simply a group of independent characters who interact in similar stories?
Also, as for what challenges to face, I've taken inspiration in the past from the children's books Jedi Apprentice and Jedi Quest series which are set in the prequel era, in addition to the Young Jedi Knights (NJO era) books. The Clone Wars show had a few episodes with a group of younglings as well, it's worth a watch to get some ideas. Plus, depending on the age, there are classic coming of age stories that can be adapted to Star Wars. There's really no end to what you CAN do.