I think she has been incredibly grown up and sensible about this.
Since September DH hasn't been able to get out of school in time to pick up DS#2 and DD from their school. So DD has been picking DS~2 up, making sure he has all his stuff, and walking home with him. She has to unlock the door and then they wait for DS#1 to get home at about 3.30 and DH about 10m later.
Now for a 10yr old that is a lot of responsibility and I think she has taken it on very responsibly. I want to get a little gift to say thankyou. Maybe a watch. Or should this just be seen as part of the normal stuff that families do for each other?