How come priest is called father and nuns are called sisters? Got any holy member called mother or brother?
An ordained priest is addressed as 'Father'.
A deacon (Priest's assistant, but doesn't have his powers), seminarian (someone who study to become priest), religious brother, are called 'Brother'.
A nun or religious sister, is called 'Sister'.
The Mother Superior of a convent is sometimes called 'Mother'. I'm not too sure about that.
Of course, brother and sister are sometimes used to address friends or people from church. Usually in a formal occasion.
isnt Mother Theresa....a mother?
ya. Mother Theresa is a mother superior of the order that she founded.