HI Canada law. I am living in Canada. I just sponsored my wife, my step-daughter ( she is the daughter of my wife from her first marriage) and my daughter. ( the result of our love)
The father of my step daughter live in Canada almost 4 years ago. He never has given a child support to her daughter when she was living back home since the moment he immigrate to Canada. Now when her daughter arrived to Canada, thanks to my sponsorship he go on in the same situation.

I am responsible for all my family. Before god and I signed a document to immigration as well when I applied for the sponsorship that specify my responsibility.

My question is: , Can my wife legally ask for child support to the biological father? He is living in Canada and has another family. He visit her daughter but never has provide any financial support to his child.

Thanks in advance for your answer.

Does she not already have a child support order in place, she can merely ask for that one to be enforced. But of course she can ask for a support order if she does not have one.

His child support has no bearing on you promise to God ( that is not a legal binding issue on earth) and immigration is to be sure child is cared for in Canada. It also has no bearing on her legal rights to collect support.

As far as I know there is no place on earth that doesn't require a parent to financially support their children. If your wife has never gone to court for child support, then she can do so once she establishes residence in Canada. If there is a court order in another country, you will have to check to see if Canada will honor that order.