She's really an amazing little girl!
Have you looked online for mazes and worksheets? Is she asking for harder things or do you just think that she needs to be challenged? DS isn't challenged at a lot of games that he likes to play and worksheets that he likes to do but he's fine with it. He also finds ways to make things more challenging. A year or two ago when he was starting to read really well he'd do things like turn the book upside down and read it that way or when he's writing his name for the 1,000th time for homework he'll make patterns out of the letters.
I agree with Legos and Tinkertoys and things like that. Those can keep him busy for a while.
