I'm not a lawyer but just an advice. I forgot to fill out a document about my compulsory military service and they found out I had to fill one out. If you and your spouse are inside Canada, and have no dependants outside, why getting your PR a little late should be a problem? I don't mean you shouldn't care but I think it is better to be true with your documents, since they can probably find out that you are married.
I live in Canada and my wife lives in my home country outside Canada. I have a conflicting statements from two lawyers. One said I don't need to add her to my already application and I need to wait to get my PR before filling for her. While another lawyer said i should add her to the process now. Am just confused as to what lawyer to listen to.