In theory, since you haven't landed with your COPR, your application is not final. And you are not PR until you landed (thus you are not sponsoring)Yes, I got in a common law relationship after I received my initial approval. However, my application was on hold last 2 years.
So, in this case, I am not sure if it is a sponsoring or not.
If it is a sponsoring, the official website says I cannot sponsor her since I am currently living outside Canada.
So you are updating your application and adding your common law partner.
But I am not familiar with COPR extension and not sure if that's any difference from the normal not landing with COPR because of status changed. And adding spouse/common law partner before getting the updated COPR to land.
Maybe there are more people with similar experience in the PNP and EE section of the forum.