WHA to EU1FAM Transition Help

Hi!

I am an EU living and working in Ireland and I met my Canadian partner in Ireland. She is currently on WHA and her work permit is expiring October 2019. She is currently employed with a contract ending January 2020 and she does not want to have to leave or quit her job for financial issues.
We have some questions regarding the transition from WHA to EU1. We are getting married mid August and will hand in our application for EU1 end of August.

I heard it takes time to receive the temporary stamp 4 letter in the mail.... if we do not receive the letter in time by October, will she have to give in her notice at work / leave the country? Or while a decision is being made she is entitled to still work or live here?

Thank you