Yichen. I would listen to you lady teacher. There is no wieght until after the foot os flat on the floor. The feeling is like squashing a soft fruit. As the weight is transfered the front knee should turn inwards slightly, still with a nice leg line, and a high instep.This is when you pass the hip over. I would watch for this with your teacher. Don't forget to have both feet turned out. see if she very nearly gets a toe to heel on that backward step. No gap between thighs. With all that you still have to smile. Good Luck.