[ ] Welcome Sofia in Karak Eight Peaks. Show her the wonders of this legendary Dwarf hold. Take her to a meal in the best halfling restaurant you know of. Give her access to the library and introduce her to The We. Show her the view from your tower. Introduce her to the other wizards, and leave out the unfortunate circumstances of her past. Make it clear that this is, in your mind, not of the last chance for a troublesome apprentice but instead the beginning of her time as a wizard of Eight Peaks.
Idk, something like this? We don't need to make any threats, if she touches the bad magic Mathilde will kill her. She is ~20 years old and a known magic addict, she knows this and we would insult her intelligence if we try to deny it (which is why I'm against taking off our hat). But I want to give her the best chance she has got for that to never happen. The Jade college most likely tried to discipline her for the last few years, and all that pressure, while she went from "probably kidnapped and future dark Wizard" to "suspicious apprentice" to "known magic addict", never amounted to any change for the better.
She went from one shitty situation into the next and never really caught a break. This can be her chance to take a deep breath, recenter herself and finally leave all that bullshit behind her. And she wouldn't be the first wizard that found out what kind of person they are while in Eight Peaks, away from their prior troubles. Mathilde was aimless before she joined the expedition (not to mention her beef with Roswita and Sigmar). Hubert hated being a (celestial) wizard. Panoramia used the distance from her family to figure out where she stands and built something great together with the halflings. I want to give Sofia the chance to do the same. This in my mind strikes a good balance of telling her what we expect of her as Senior Wizard of Eight Peaks, without threatening or infantilising her. I trust that Panoramia, as her master, manages to deal with everything else.