This Q&A podcast episode addresses why Charlotte Mason included Arabella Buckley's books, how a child can come to the history rotation and always be in exactly the right place, and why all advertised Charlotte Mason curriculum does not necessarily fit in her feast.
By Arabella Buckley! https://www.amblesideonline.org/PR/PR10p455ObservationNature.shtml
Or this mentions her too:
https://www.amblesideonline.org/PR/PR04p017LessonsMothers.shtml
But I would love to hear if you have a different article in mind!