By all means call me Diamond. I've been called worse (LOL).
My apologies to purplepeg too.
I just checked my American Girl box. There is a small white label where the return address that is typed on it clearly says American Girl and their address. But I would say it is in a font of about 14 points. So pretty small. Luckily for me the express post label covered the words American Girl.
On that same label there is a small box where you write the description of the items in the box. They wrote "Doll Clothes". But they wrote it in cursive and they wrote it pretty small. DD never would have been able to read it if she had taken the time to look at it.
Luckily DH has his own business from home and gets boxes fairly often. So the kids didn't even glance at it in our front hall when they got home from school.
So in conclusion, (why do I feel I'm writing an essay for university again?) I would say that you have a good chance to get the box right past your DD without her knowing it. Good luck and may the force be with you