Ms Trad denies any wrongdoing and has previously said she met with two candidates for the position at the request of the Education Department.
A senior Education Department executive wasstood aside on Monday night in relation to the matter.
Ms Grace said she was not made aware that the meeting had taken place until it was revealed in the media.
"I was not informed about that meeting at the time and ministers do not play a role when it comes to an independent process for the appointment of a principal,"she said.
"I was made aware at a later stage that had occurred."
When asked if she was annoyed after hearing of the meeting Ms Grace said:"After having nearly 40 years'experience in industrial relations,I know that you have to abide by the proccess and I expect all of my officers to abide by the protocols and the proccesses."
"Whether[the meeting] was approporate is a matter for the CCC,that is why this matter is being fully investigated that is why a senior executive of the department has been stood aside,"she said.