A rainy day googling has brought up many references to this as a solo flight, including articles she posted herself on her facebook page.
I have to wonder, were these organisations in on it were they duped as well?
https://amyjohnsonproject.org/news/t...ght-australia/
https://www.businessairportinternati...xpedition.html
Boeing: Boeing Supporting Curtis-Taylor's S. Africa-to-UK Flight in Vintage Biplane