I really don't know, as I collect faces from the web, sometimes from Pinterest and other times after seeing a famous model's face I will look for other images of her... that one may actually be a drawing, and I modified it slightly, and have also added blush to her cheeks now. If I know whose face it is I will often say; for instance, I have used Emmylou Harris' face, Audrey Hepburn's face, Katharine Hepburn's face, Joni Mitchell' s face, Marilyn Monroe's face... I did a Star Wars one and used Ewan McGregor's face paired with a body modelling his movie outfit... I also received permission from a couple of the women here to use their faces 
A lot of my content pieces come from sites that off such things for free so people can use them in personal projects as long as there is no commercial gain. I spend hours on such sites combing through what they offer in various categories.
That last one is a mannequin's head to which I added hair and changed her facial features,
for example the eyes, to be looking at us instead of away, and changed her mouth... as well
as adding wings, a body, and dress, which is actually two dresses blended... etc, etc
A lot of my content pieces come from sites that off such things for free so people can use them in personal projects as long as there is no commercial gain. I spend hours on such sites combing through what they offer in various categories.
That last one is a mannequin's head to which I added hair and changed her facial features,
for example the eyes, to be looking at us instead of away, and changed her mouth... as well
as adding wings, a body, and dress, which is actually two dresses blended... etc, etc
