Because I started school at 7.5 back in the USSR, and was in a largely non-academic environment before that, in my mind 'school age' is around 7, which helps a lot.
Now as DD is turning 9 in two months, I do worry more. She is not a typical unschooled child you will read about on various forums. She has no interest in academics, she is a perfectionist and seems to give up easily. Even when she herself chooses to focus on something, she gets very emotional when things don't go as expected, and she doesn't like to 'follow'--she tends to find her own ways in doing things.
Things that she's tackled on her own were origami (following instructions for very advanced patterns); sewing animals, and now crochetting animals (by animals I mean 'horses' and an occasional crocodile for her brother ). Her understanding of spatial patterns and relationships is truly amazing, in any case, much better than mine.
She reads well, on the level, in English and Russian. She is not into trying books that are somewhat above her level, as she actively avoids anything that is remotely sad or scary--and many things are either sad or scary to her.
At my last freak out we started math when she was 8.5, and her grasp of concepts was really good, but she hated it, and we are taking an exteded break. She's 'behind' in math. She's working on her handwriting, but it is currently 'behind' as well.
I'm sure she has enough of knowledge about a bunch of other things, but we've never done anything remotely formal--just reading books, watching DVDs, discussing things.
Well, the bottom line is, the older she gets, the more I worry. But I try not to...About my 6 yo--I don't worry at all.