Sorry, but you are wrong. Both parents must be citizens if you want to be ‘Natural’. Go research Vattel and David Ramsey’s input. They were the authorities. You might learn something.
http://en.wikipedia.org/wiki/David_Ramsay_(congressman)
Unfortunately, wikipedia does not supercede US code. Look up that.
The two-parent thing only comes into play if the candidate for prez is born outside of the US.
Even there, it’s not as simple as both being US citizens.
See:
http://www.usconstitution.net/consttop_citi.html