Is it permissible for a girl to wear trousers with a long, loose blouse, and is it obligatory to cover the the top of the foot, and what is meant by it?

A woman may wear trousers provided she does not imitate men or disbelieving women. Furthermore, she must wear over them a loose and long garment that covers the feet. It is not sufficient to merely wear a long blouse over trousers, as this does not achieve complete concealment.