If the adults allowed girls equal access to play with the cars, they could, either explicitly or via the fact of girls playing with the cars, negate that notion

If the adults allowed girls equal access to play with the cars, they could, either explicitly or via the fact of girls playing with the cars, negate that notion. My mother in law tells the story that when her kids were small she was determined to raise them free of sexist gender norms. One of the things she did was get some dolls for her son and, for a few hours a day, she would hide his cars to make sure the dolls got equal time. This lasted until one day she looked into a room where he was playing with the doll by running it along the floor yelling "vroom vroom!" She brought out the cars and that was the end of that.