"So it would seem." He agreed. Well-hidden would have been an understatement. For a fleeting moment, Caractacus debated asking her why she had done so in the first place, but he refrained, instead passing the gobstone between his hands and feeling it. Ms. Prince's magic was still fundamentally the same, that resonating frequency which prickled his arms, but it was wilder, less controlled.
A person's magic would change, evolve, but underneath, the core remained the same, excepting truly drastic events. So the stone was still recognizable as Ms. Prince's.
"I would not suggest you go barefoot. You may wish to choose footwear that allows your students to speak with you without a horrible crick in the neck, however." He smiled indulgently and answered her tease placidly, "No thank you, Ms. Prince. That would not be appropriate."