Please tell me the difference between the usage of
1-anyone always refers to a person; it means 'any person at all'.
Anyone who knows her could tell you how kind she is.
2-any one can refer to a person, an animal, a plant or an object.
Any one of her friends could tell you how kind she is.
Any one of the cats could have eaten the mouse.
She would be very happy with any one of those diamonds.