When does a woman become a mother? Does it happen during pregnancy? Or with the onset of birth? Many years ago I wished a happy mother´s day to a friend of mine, who was then pregnant for the first time. She replied 'I am not yet a mother’. Until this day her words come back to challenge me. What was going on inside her mind? After all, she was already a mother in my eyes. Now I know. She was preparing to be a mother. Daniel Stern describes three phases of becoming a mother.