It is extremely unlikely that a windshield would break from someone hitting it with their head. Windshields are made of tempered glass, which is designed to be very strong and resistant to breaking. Even if someone were to hit the windshield with a significant amount of force, it would be unlikely to cause the glass to shatter.
If you heard a noise when the girl smacked her head into it I would say it was her nose/skull hitting it not the glass.
