Yes, real friends should say your faults in private because it is very important to understand your mistakes without feeling shy. A real friend should not show your faults to the others, but to you. Understanding your faults is an important way through finding solutions for them.
Privacy is very important for a friendship. The friends should share their thoughts and feelings without letting the others know. Especially the negative aspects should be shared only with the friends.
A real friend would give you advice and would try to make you better. A real friend will not show your mistakes to the others and will not make you feel bad in front of them.
