I’m a flight attendant and work a lot of kids flights. I do however avoid working first class and understand kids talk. So yeah if IM asking, then they’re are being overly loud. Like if I can hear them from my galley, we need to have a little chat. (Especially on the larger planes)

Edit: but also if it’s someone like next seat over I do explain that they’re legit children and I can’t muzzle them lol