Well, OK, to speak more strictly, she actually misattributed a quote to GKC, it would appear. But still....
https://www.facebook.com/watch/?v=10156164832444273
J.K. Rowling also once misattributed a quote to GKC on Twitter (that someone had first misattributed to her), and ironically enough had the hashtag "#CorrectAttributionDay" :-)