Yes, you can go to the Chinese Embassy in Canada which is located in Ottawa. There is no requires to show that your family member should all be present while applying for the Tourist/Family Visa (L visa). In addition to passports, visa applications and recent passport color photo with white background, you may choose to take certificate to show your family relation. It will be safer. One thing to note that Chinese Embassy and Consulate-General will not issue individual visa for tourists who will pay a visit to Tibet, unless to contact a local travel agency to obtain confirmation for group visa with at least 5 people.