I was poking about in the File Editor a while ago, and noticed the "GoodInSubject" field for teachers. I'm not aware of anywhere in the UI that exposes this, and I don't think VEE can interact with it except perhaps via one of the lower-level operations.
Is that actually used? Is it perhaps a legacy of a pre-teacher-experience system? Or is there some "hidden" behaviour for this value, or perhaps it's an output and changed as the teacher's experience grows? I recall the entire teaching system is in the compiled codebase, not VEE, so I can't easily answer this question myself.
The main reason I flagged is that April Raymund appears to be the only teacher whose GoodInSubject is not their starting highest-skill subject. Of course, if it's updated over time, then the starting value won't matter.
The value is kept for student & teachers only, but not really used for anything.
For generic students that pass the FavouriteSubjectChance check (defined in scenario config) it's set to the subject they gain a stat bonus in at generation.
So I guess you could read which it was (which is their favourite) in VEE via 'Get Property by Name' for some flavour text.