From what age should a girl observe hijaab and wear niqaab?

Answer

It is compulsory for a woman to wear niqaab in the presence of ghair mahram males (strangers). When a girl is six years old, she should wear Hijaab for ghair mahrams who are not relatives. When she is seven years, she should adopt hijaab for ghair mahram relatives such as male cousins, including donning the niqaab.