TRV expires: extend TRV, and sponsor from within Canada?

[DJ_Bobby_A]

Dear all,

I will be a new PR and will land in Montreal in the beginning of September.
My girlfriend will enter Canada around September 15 with a TRV. Her TRV expires October 1.
In the meantime, we wish to get married in Quebec (takes 20+ days), and I will sponsor her for a PR visa.
Is there any way that she extends her status during such a short visit?
If she goes out of status, will that have any consequences in the future?\
Finally, is it wiser to sponsor her from within, or from outside Canada (around 6 months)?
Any help will be appreciated. Thanks.