Even when she was younger, she was such a perfectionist, that she would take way longer to complete an assignment than was necessary, and would do way more than required.
Some kids are just more detail-oriented than others.
Whereas other kids might do just the minimum to get by, these perfectionists will work hard making sure everything is perfect. I'm looking forward to seeing what everyone else has to say on this topic, since it's been one of ours, too.