When did Christine join the band?

[Villavic]

I just found an article from a chilean website (in spanish) that mentions Christine joined Fleetwood Mac on August 6, 1970. Is that correct?

Mick mentions in his first book Christine entered briefly during the Mr. Wonderful sessions (1968). Then the most formal date is around august's first date, 1970. But I didn't find anything about a specific event on august 6 (an announcement, a deal's signing, etc.). Does anybody has more info?


Mick's book:
Although Fleetwood Mac was officially a four-piece band when we cut Kiln House, we had help from the retired Christine Perfect. Not only did she draw the cover art, but she also sang and played on some of the tracks. By the time we finished the album, we were about two weeks away from a three-month tour of America, which began the first week of August 1970. We were worried because we were used to a three-man front line and our sound was thin without Pete. So, at the dinner table at Kiln House one night in late July, I asked Chris, "Do you wanna join the band?" She knew we needed to fatten our sound and she knew all the songs anyway, having been forced to listen to them endlessly in rehearsal. So she came with us on the Kiln House tour. Her first gig with Fleetwood Mac was at the Warehouse in New Orleans on August 8, 1970. We did all the stuff on Kiln House on our little Fender twins, and for the second part of the show Jeremy would play blues and some oldies.