by Jonny_Blueline
The strengths of the series are the detailed physical interactions, use of foreshadowing (especially early on), and the group dynamics of the quartet. Subplots with ensemble characters are fine so long as the plot threads tie back in with the core characters and the main plot does not get washed out by the side trips. I agree with others, keep the parents and kids separate, but don't hesitate to tie in the "Gang of Eight" gradually, using good characterization, foreshadowing, and plot pacing.
You've found a good formula and this series has plenty of potential plots left to run -- I hope you continue writing!