It is not a question of doing things with or without permission but doing them consciously and knowing the implications of our actions. One should not do something because someone tells us to do it nor because it is a thing in fashion and everybody is doing it. Whatever we do should be done because one has given it a thought and feels it right within one’s heart.
Your sister and niece should sit together and discuss these things logically with the pros and cons and the possible consequences. Then the final decision should be taken by the niece after giving it due thought and consideration. Yes, over protectiveness is not good as it may take away the needed confidence. But equally nothing should be done unthinkingly like Panurge’s sheep as that is equally not good for the development of our individuality.
Affectionately,
Alok Da


