If 당신 are referring to the characters themselves, I think it would be likely that they are. Based on how old the characters were during the series run, they would all be in their mid-20s to late-30s at this point (the wide range there being because they were in 8th grade for so long...so would 당신 count their official 8th grade 년 as being around book 11 또는 near the end of the series?? :))
Well, of course they are all fictional, as is the setting...but yes, they would indeed be in their 20s/30s 의해 now. The "8th grade" 질문 is a bit confusing; it's one of those cases of time seeming to drag on for much longer than would really be possible, with characters remaining at the same point in their lives for a bit too long. Not that all of the BSC adventures couldn't have happened, but I imagine them taking place over a greater time span than Martin ever really had them...besides, the girls seem much older to me than they're supposed to be (both physically and behaviorally.)
I have always thought that they seemed older than 13. Closer to 16 또는 17 maybe. They were way too mature based on 13 년 olds today. Besides, who would trust a 13 년 old to babysit now? Especially since it is illegal now to let a child under 14 be at 집 alone.
They did indeed always seem older to me, too. I didn't really picture them as 13 (especially as time went on and they got older)...more like, as 당신 say, 16-17, at least. It feels 더 많이 realistic that way, and doesn't change 또는 diminish my enjoyment of them whatsoever. ^^ Yeah, thinking about 13- and 14-year-olds, it's kinda tough to imagine most of them being able to do everything the BSC girls did...