You can a couple things. You can marry her and sponsor her as a spouse.

If you don't want to marry, you have to live together for at least one year straight so you can apply for common-law sponsorship. If she has not used a working holiday visa for Canada that is a good option. https://www.canadianimmigration.net/work/holiday-visa/#:~:text=Working%20Holiday%20Visa%20Canada,a%20job%20offer%20to%20qualify.

The Working Holiday Program does not require a job offer to qualify.

As I see it working holiday VISA basically allows them to stay in Canada doing whatever they want (they're technically suppose to work I believe, and she should so she can make money). So during that you can live together then apply for common law after you've lived together for more than a year.

If she already used her working holiday visa you can do a working holiday in America then apply for common law sponsorship in Canada.

Or just marry her.