You'll learn that Canadians also have a constitution to protect them. In particular, Section V.38 of the constitution details the procedure for amending it. It's quite similar to the one for amending the US Constitution. As I'm sure you are well-aware, parliaments don't meet in secret any more than the US Congress does, their laws don't take effect before they are made public, and are no more "flighty" than the US Congress is. The difference between Parliamentary and Presidential democracies in any case is not in the way laws are made, but rather in the independence of the executive.
The solution to the social problems of very traditional societies is exposure to the outside world. The coersion you describe already exists -- except now these women don't go to any court at all.