I am a Permanent Resident of Canada for 4 years now. I am currently on maternity leave and would like to invite my father to come and visit me so he can see his grandchild. Problem is, he cannot travel alone. So, my brother will come with him together with my sister in law. How do they apply? individually or apply together as family. If so, who will be the principal applicant? Will appreciate your help. Thank you so much.