We are total fans here at the McClelland Lookout.
I love it...
As for Aaron being young... my idea is that scene was before the point when Jack gets hooked on the drugs. Its soon after they get home.
Also, remember, although the show itself has been on for 3 years, the timeline for the show is just 6 months or so. Thus, Aaron would be anywhere from 6-8 months to 16 months (guessing) when that scene was shot.
I really like the show, mainly because of the "you never know whats gonna happen" part of it. Keeps my mind thinking (and some days, its what I need).