Antonia Forest fans

Presuming Miss Cromwell's form is the only one in which officers are appointed, Marie was well-liked enough by her peers to be elected prefect in the Second form (Autumn Term), but during the course of that year managed to alienate them by being 'bossy'. Maybe that during the course of that year she started to feel some of the symptoms of the heart condition that will eventually kill her: maybe they manifest as something like a panic attack--racing pulse, breathlessness?--or as weakness and lethargy--so she doesn't see them as health issues to be reported to Matron? Or maybe she does and she's dismissed or misdiagnosed? She might be naturally a bit bossy, but when these scary and/or painful things start happening she ramps up that bumptious side of her personality to feel in control, producing that off-putting heartiness? And her schoolwork starts to suffer, because she often feels ghastly, landing her eventually in Third Remove. The condition might also change her appearance a bit, producing the clammy, unappealing effects that Forest describes? I haven't researched any of this in the slightest, so I don't know if there *is* a medical condition that might cover these bases, but I do feel the need to read Marie against the grain sometimes.