Can I help my mother sue my father for child support for his four child by her?

my father was abusive to my mother and his four girls by her. neither of us have seen or heard from him since I was about eleven years old I am now twenty. My knowledge is that he currently lives in El Salvador. My mother and sisters live in Ottawa, Canada. I am aware this money is not owed to me but I would like to help my mom get what she deserves. My mother hasn't seen a dime from him ever, even when he lived with us for eleven years in Canada.

he may have assets or taxes owed in Canada. Start there and file a basic lawsuit to attach a lien on anything he may have in Canada. As for El Salvador not sure but if your Mom goes to Cnada welfare they may try to help. They did for my Mom.