I suspect the series may last for 10 seasons, I think it'd be hard for a TV series to make it much past that without starting to get too stale and at some point they'd need to have some serious time-jumps or better track show-time with real-world time so that the ages of the characters don't clash too much with the age of the actors. Carl is still ridiculous, he's a teenager and in show-time it was only two years ago he was in grade-school awed by a deer in the woods.
I hope that they just ignore Carl's age like they have been doing until now. No need to reference it. They've already cast other teenagers in the show to be same age as Carl instead of younger kids so they seem to be doing exactly that. They can just grow up Judith if they need younger kid-characters in the show.
They could've let more time pass in the prison and age Judith. It would make Carl's rapid aging look less ludicrous.
That's kind of it. Ignoring Carl's age pretty much changes huge chunks of the show into not making sense. It's only been inside of a couple of years since Rick woke up at the hospital, Judith's age plus a nine to ten month gestation period. Chandler Riggs is 15, if he's the same age as Carl "now is" due to what we'll consider soap-opera aging this means he was 13 when he got shot in a forest because he was awed by a deer.
He couldn't handle being out of the house alone without people wondering where he was, he was picked up from middle school/Jr. High the day his father was shot, not grade-school.
Think of everything Carl does and says in the first couple of seasons and think if any of it makes any sense being applied to a 13-year old. That's the age of my niece and I can't see her being so captured by a deer in front of her and gushing over how beautiful it was.
Now, we could argue we're at a tipping point, a point where maybe Carl being that age can *almost* make a tiny bit of sense. But only almost. Because at some point, especially if we don't have a meaningful time-jump a lot of this "young Carl" stuff is going to have happened when he was a teenager which is going to make the early part of the series kind-of look silly, especially on a re-watch. Lori was sitting outside Carl's high-school talking to a fellow parent about her marital troubles when Shane rolled up to tell them about Rick being shot.
How many mothers pick their child up from high-school?
How many teenage boys are stricken with awe and wonder over a deer?
So either we need a time-jump, or Carl is going to need to die in order for the series' time-line to make any kind of sense. They can keep getting babies of varying ages to "re cast" Judith who's essentially a prop at this point. But what's going to happen when there's an 18-year age gap between present-day Carl and present-day Judith?