Blocks and bricks
Building blocks and bricks like LEGOs, Mega Bloks, Tinkertoys, and similar products help to teach kids about spatial reasoning in three dimensions and following a plan (for example, building the design on the box), as well as facilitate fine motor control. Like engineering toys, they also provide children with materials that help to bring their imaginations to life. Unfortunately, blocks and bricks were historically marketed primarily to boys, but this has changed recently with the introduction of the LEGO Friends series in 2012 and similar product lines from Mega Bloks.
Petals and STEM carries a wide variety of blocks, bricks and building sets designed for girls. Some of these products simply use pink color schemes (e.g. Tegu Tints), while others (e.g. Mega Bloks Hello Kitty series) include characters that tend to appeal to girls. No matter which ones you buy, don't forget to knock down your structure when you're done building it - that's at least half the fun!