I cant believe they would charge for a non player.
My wife and I go to the golf course each year on holidays, I will pay a much higher green fee just because it is holidays as a treat to myself. My wife loves to watch and will come along.
If she had to play I will find something else to do.
If a course can make a profit with me by myself in a cart then they can make the same money by having my wife as a passenger, they will make double from meals and drinks too.