That sentence you quote means if you intend not to include anything about your family members in the package (even the forms), you must have a declaration. Otherwise, you will be deported even you get approval. This happend before, one guy did fill any information about his wife because they were planning to divorce. Five years after his staying in Canada, immigration officer found this problem and deported him.
So, you have to provide your family's information, no matter they will go with you or not. I remember in form of personal information, there is a place you can choose this family member will accompany you to Canada or net.
You can apply a passport for your kid in China, it's very easy.