I saw this linked in another thread...I've never actually looked at AoPS:

http://www.artofproblemsolving.com/Wiki/index.php/AMC_8_Problems_and_Solutions

It seems like the older ones are a bit easier? DD could definitely do some of these solo. Many she could work through pretty easily with a little bit of help. Would that be indicative of mild math talent (one grade ahead is where she is working now) or something a bit more out there in an 8yo? What grade level are these for? (I have no idea, honestly.)