Tractors and trucks
Although trucks and tractors aren't STEM toys per se, they help to familiarize kids with building and construction, and they also have educational value for illustrating principles of velocity, momentum, and gravity. It's unfortunate that Caterpillar doesn't make real pink bulldozers, but shouldn't stop your little girl from having a pink digger of her very own!
At Petals and STEM we sell a variety of tractors and trucks designed specifically for girls, including both small-scale toys and larger ride-on items. Have fun in the sandbox!