It would really depend on where she's coming from. If she is non-visa-exempt and requires a TRV to board transport to Canada, it will likely be refused because, by virtue of having applied for permanent status, she can no longer demonstrate temporary intent.
If she is visa-exempt, it's best if you accompany her when she tries to enter Canada - to speak to your qualifying relationship, your intention to be her sponsor, and your promise that she will comply with the requirements of her temporary stay. She should not try to enter alone with a PR ap in process.