She came up with the right idea

Cars: Legacy

Studies have shown there's a difference in play of infants across varying cultures. Basically the male and female brains are different from nature and this difference is amplified by nurture.

Hey, this guy is cool.
If only he didn't get her some weak ass Hot Wheels.

Soft audi, warm audi, little ball of steel.
Happy audi, sleepy audi, wheel, wheel, wheel.
I know that sucked but meh ¯\_(ツ)_/¯

That's a good idea! We don't determine their genders, they do.