I'm guessing from your other posts that your spouse is applying from India. The India guide says
• Send originals of the immigration forms (item 1) and police certificates.
• Send photocopies of all other documents, unless instructed otherwise.
• If your documents are not in English or French, send a notarized (certified) translation with a copy of the originals.
So if all of your documents are in English, you DO NOT need to notarize anything, it is simply a waste of money