Why would you need to get married again in the US to "make it official"? A marriage ceremony in Canada is legally binding if performed by someone licensed to do so by the government. A legal marriage in Canada is legal in the US (except unfortunately for same sex partners).
You will not be able to just turn around and have her enter the US immediately following the ceremony. You will have to petition for her for a spouse visa. Either K3 or CR1, both of which take about a year to process. Once you're married, if she turns up at the border with all her worldly goods and a flashy new ring on her finger, they'll deny her outright, and possibly ban her until she gets the proper visa.
For marriage based immigration info to the US please see
http://www.visajourney.com ALL the information you need is there, including message forums, example forms, and detailed guides for the paperwork and how to choose which visa is best for your situation.