It’s been a while since she told anyone what grade she is.

↓ Transcript
<A bit later, Gregor, Katharina and Halen are talking about the council meeting>
Katharina: They are doing NOTHING?!
Gregor: Hrmfh. I shouldn't have expected anything else. They're all so deep in Amanda's pocket it's a wonder they didn't try to make HER mayor yet.
---
Halen: At least Lord Bertrand was concerned, wasn't he? And the others are just ... CAUTIOUS. They'll change their tune once captain Slania has officially confirmed our story. I'm sure!
Gregor: Don't be naive Halen. The Guard Captain has her own plans, even if they don't align with Amanda's. We can't trust ANYONE.
---
Katharina: But ... this is a GUILD CITY, isn't it? We are supposed to govern ourselves, WORKING TOGETHER with the local families! How did it come to be like THIS?!
---
Gregor: I ask myself the same question all the time, Miss Grauch ...
Katharina: <getting angry> Well ... then what are you going to DO about it?
Gregor: ... excuse me?
Katharina: You heard me. WHAT ARE YOU GOING TO DO?
---
Halen: Katharina, maybe we shouldn't -
Katharina: NO, Halen. Gregor Peck, you are the GUILD MASTER of this city. And for some reason also the MAYOR. The safety and peace of this place should be your PRIMARY CONCERN. But all I hear is complaints about how the whole world is against you, while you do ... WHAT, exactly?!
Gregor: Do not talk to me like that, girl!
Katharina: I am NOT a GIRL! I AM A FOURTH GRADE MAGICIAN!