I’ve kept my mouth shut for awhile on speculating about her mental issues, but I agree with a lot of this . I’d like to finally sperg about it because I can’t come up with a conclusion, but maybe it'll help someone else. The symptom that I’ve always focused on, with Chantal, was the well known jumping into new interests or plans with precise focus, but the next day completely disregarding them. That’s not a symptom of ADHD at all, and with OCD sufferers it’s almost always something that’s egodystonic (Seen as bad, unnatural, and recognized behavior by the person with the disorder), but it’s definitely a red flag for OCPD.
OCPD sufferers who pursue an obsession on a whim with a well thought-out plan, that they never follow, typically don’t recognize it and it’s egosyntonic (Acceptable to the aims of the ego and the related psychological needs of the person (for example, a delusion);). One reason I’ve never thought she had OCPD was because she lacks most of the symptoms. (I.E. Being a work-a-holic, pursuing new short ventures and sticking with them, orderliness, and cleanliness) And because your first sentence is true. So I still have no idea what illness she would fit into, but the temporary obsessions fits OCPD to a tee and isn’t so common with OCD or ADHD. An OCD person would probably stick with those plans for a good while.