Agatha didn't hold back any information in front of this benevolent being who had acted to save Frost from destruction. She laid out all the intelligence she had gathered thus far.
Some of the intelligence was what she had observed and deduced during the Mirror Frost operation. The rest came from inquiring with various priests and her own trusted subordinates after she had returned to the cathedral—events that had transpired while she was trapped in that mirrored city.
They were things "another her" had experienced.
The boiling gold mine upon which Frost depended hid a massive secret. The so-called boiling gold ore had been exhausted since the era of the Frost Queen. Successive governors might have been in possession of a tremendous secret. Governor Winston and "another Agatha" had vanished deep within the mine, and before their disappearance, "another Agatha" seemed to have uncovered some astonishing truth, a strong surge of her will that had even reached the true Agatha...