My first question is - How can i report to the domestic violence dept of Toronto .. if any such situation arises .. i am in US.
You, or she, can just call the police. Explain that she is being beaten by her husband, and police officers will be sent over. If she is in the middle of being attacked, or hiding somewhere in fear of an attack, she can call 911.
second question - She has her PR from last one year .. is she by anyways dependent on her husband?
She is not dependent on her husband. She has her PR already, so can stay in Canada even if she leaves her husband. If she has no money, she can apply for welfare. (Her husband will have to pay this money back to the government up until she has been a PR for three years.)
third - We have recently got our PR and are still waiting for our cards which are addressed to her house .. so can we somehow change our PR card address
They should arrive soon. If she is in danger she should not stay just to get the cards. You can change the address you want them sent to. Also, you should be able to travel to Canada even without the cards. Maybe ask at the nearest Canadian embassy about how to do this.