It is probably easier for you if you get married before she applies for PR. Then she can apply for you at the same time.
You must be very careful that if she applies for PR before you get married and you get married while her application is being processed, she must let immigration know immediately that she got married to add you to the application. If she doesn't tell them and gets her PR while they think she is still single, it will be seen as misrepresentation and she will never be able to sponsor you.
Another option would be that she goes through with her PR completely and then marries you after she gets her PR and sponsors you right away.