Unidentified Jane Birkin photograph

I recently found this photograph of Jane Birkin (it looks very much like her on the right) and two other unidentified actresses and I wondered if anyone knew who the other actresses are and what the photograph is for or from?  If anyone has any ideas, please let me know.

UPDATE 14 JULY 2017 – I have just discovered that this is a photograph of Jane and two other girls (the blonde is possibly Natasha Pyne, not sure about the brunette yet?) who all play art students in Daniel Petrie’s 1966 film The Idol, which stars John Leyton and Jennifer Jones.  What an absolutely amazing find, eh?

Here’s a screenshot of Jane in the film with her “boyfriend” who looks very much like Jeremy “Boba Fett” Bulloch!