If your girlfriend gets a visitor visa, and then you get married in Canada you could then apply for PR for her. You could apply inland and she would be able to stay here and get a work permit after about 6 to 8 months. She would NOT be allowed to leave the country until processing has been completed, if she did leave her application could be considered abandoned.
She could also apply outland in which she would have to keep extending her visitor visa (no guarntee) if there was an interview she would need to go back to the Philipines. She would not be allowed to work. It is a faster process overall though.
The choice is yours.
