Nina, a 6-year-old, states that she won't play softball, soldier, or explorer because they are boys' games. she will only play school, house, or ballet dancer, stating that these are girls' games. nina could therefore be described as

The correct answer is gender schematic. 

A person who is gender schematic is someone who views the world in terms of traditional male and female gender roles due to their preexisting gender schemas. For instance, they see boys as tough, sporty and active, and they see girls as gentle, showing a preference for domestic chores and caregiving. Since Nina only wants to play "girl games" and not "boy names", she is gender schematic.