I am an international student, he has a work permit and our son is Canadian. They are not going to work or get paid. They will help me temporarily for a few months as I have to work from home and study at the same time. This is my last term at school and I need their support in this tough time until end of april. This is not babysitting it is family support.
Unfortunately you'll need to try to find other arrangements like other parents in Canada although you could attempt to apply again but chances of approval are not very good. Even unpaid grandparents taking care of a child is considered working because it is taking a job away from someone in Canada.