If you want to cancel her as a representative, anyone who appointed her: sponsor, PA, dependents 18+ need to sign use of a representative form again filling parts A, C, D and sending those through their webform
About the GCKey linkage, I'm not sure if you can call CIC and ask them if they can revoke her access if she got cancelled as a representative, call them and ask if they can do so
you don't need to link your aplication online to know updates, my application isn't linked online and I check my updates through calling the CIC number and using the automated service and using ECAS
I feel it's best if you got rid of her she's making it harder on you guys and she's not helping, she just cares about your money and that's all
It's very saddening when I see representatives like this taking advantage of people, it's shameful, where's their integrity