Trust me trotter, it had an impact on me, and if I am not mistaken, I am the same age as your daughter. I was in 6th grade, english class, 15 minutes into it, we went into lockdown as requested by the state. Needless to say, the staff had no clue for about 40 minutes as to what happened. Once they found out, we came out of lockdown because if someone was attacking the states what good would a school do in protecting us. We all sat and watched the tv the rest of the day, we had class, but every class was focused on the tv, switching between classes in the school (close to 40 class rooms per grade, 20 students a room, 4 grades) was quiet, you heard nothing other than quiet walking. Most all of us thought another country had started a war with the states when we first heard it. It honestly scared most people.
From that moment on, I noticed prices on things going up, fuel for starters, yea, I remember the price gouging, but I also remember it NEVER getting back to what it was at, ever since the attack. In the end the attack IMO has resulted in the collapse of our economy. It wasn't just the banks that had a hand, with the higher fuel prices driving everything else in cost up, things had to eventually stop and fall apart.
So yes, it has had a huge impact that us younger folk can remember, at least, for the ones that cared enough to remember. I would say most schools didn't allow the news due to the images, but, our school, while complete jerks, allowed us that week to see what was happening. I still remember, but I also refuse to dwell on what had happened that day, because it can happen again, and it WILL happen again some day, just when. This is why the "War on Terror" is pointless to me, you can never get rid of every soul that hates american values due to "terror", if you do, then the country is no better than any other country that ended up on a path of war that lasted for generations, which ultimately collapsed due to that war.
But trust me, this generation will still remember it as if it was yesterday for the most part, it's just that most of us choose to not speak much about it, because the past is the past, you can't live on the past.
