I'm leaning towards letting her flower, perhaps in isolation. I agree it looks like some kind of environmental shock, but to my knowledge she has experienced the same conditions as all the others. Keep in mind though that this generation of plants were shocked by 120F temperatures as tiny seedlings. The fact that they survived, and most of them are healthy, is truly amazing. Maybe this one just never fully recovered from that. I notice also that it's leaves curl upwards at the edges. I may give it a flush and/or re-pot and see how it responds.