Blocks and building toys are fantastic, especially for someone who is interested in cause and effect. My daughter loves to build with blocks. For her first bday and xmas (just a few weeks later), she also got a a See & Say with different animal noises and a cute ladybug toy that teaches shapes, colors, numbers, etc.
Also, I sell Discovery Toys and we just came out with a brand new line this week! There are some very fun, very exciting toys that I think your daughter will love. Check out my page at www.discoverytoyslink.com/karenchao Some of my favorites for this age group are Castle Marbleworks, Hammer Away, Keyboard Kylie, Measure Up Cups, Block It, and Go Go Caterpillar.
If you want info on free toys, shoot me a private message!