Working on my edit, but just looking at these pages make me uneasy. But for you guys, I'll make an effort.
Finished the edit!
This page is set between page 11&12, just after Ciel left with the teacher to go look for the kids.
Her french is fairly understandable. I'm a pretty fair person and will concede fair points to the craziest of crazy,if it's objectively correct. However I see one problem here. She writes in Québécois french, when she should write in "Universal french", so that people from France, etc, can understand. Québecois can usually understand most if not all variants of French, except maybe the weird slangs, like from Gaspesie or something. The opposite is not necessarily true: I had to be careful when speaking with people from France & Germany. Their french is more standard.
To me, her writing is pretty clear because we come from the same place. But if I step in the shoes of someone who is not Quebecois, I can see the issue. To reiterate: By not using "Universal French", she is limiting her audience because people won't understand what she writes.
That's a good thing. Please keep writing in Quebecois. <3
Well, for the Quebecicisms:
First case:
"Fine" in french means "nice" - the masculine is "fin". It's a pure Quebecicism. Bonus: You can't write "quebecicism" without "cis". It's documented in dictionaries as a Quebec only meaning.
"Sa face" It's as you say. I'm not sure if it's use in France/Europe, but in Quebec it was probably adopted from our British Overlords, as a literal translation. It's commonly used IN SPOKEN FORM, not written.
Second case: "ami.e secrèt.e" This one is not a Quebecicism sketchy. You see, the masculine takes default, Académie Française standard. but you try to cover everyone but you screw up anyway. Basically, the masculine is "secret" and the féminine is "secrète". so "secrèt.e" technically has an error for the masculine version. That's why you don't do that. You should do "secret(ète)". maybe, but even then, comics convey spoken voice, you're not supposed to give visual cues as to the meaning via writing. Maybe in manga (in actual japanese) but that's a consequence/feature of the writing system, not the other way around.
"Piger" "pigée". This one is apparently another Quebecicism. It's used when during a draw, you pick a piece of paper in the hat. It's, the person you picked. It's documented in dictionaries as a Quebec only meaning.
Case 3: "Tu n'as qu'à lui écrire quelque chose de gentil" Again, you don't use spoken syntax in written form.
"De quoi". It means "quelque chose". As in, "something". Quebec Syntax.
Case 5: Hey, it's that thing about consent that feminism keep talking about. Vocal consent.
@LagoonaBlue I don't think it's Magnus/Ericur. You see, she says "...la carte que je lui ai FAITE". Feminine. If it was a guy, she would have written "la carte que je lui ai fait".
However. In Quebec we have a tendency to add the "e" verbally at the end of some words even if they're masculine. It's an accent thing. Verbal only. If that's what she tried to do in written form...