The Filmumentaries Facebook page posted this recently. I wouldn't say this is particularly revelatory but still pretty fascinating and important given the lack of material we have featuring Marcia discussing Star Wars and her partnership with George.

https://vimeo.com/224132896

Very nice. I had no idea what Marcia's attitude was towards the whole thing.

Also, she reminds me a little of Kim Hunter in the original Planet of the Apes.