Character Design: Forming Ada's Face- Part 1 (Playing around with shapes and proportions)

When it came to Ada's face I had no idea how to start, so I used a real refernce. I chose Natalie Portman as the base of her face. I like her facial features as she is feminine but at the same time her jaw is quite rectangular which makes her look stronger. So after working out the proportions I played around with the eye shapes, the lips, the nose, and the jaw line. It's been really helpful so far. Of course, I will intend to make her look more cartoony.
The only thing I am concerned about is that in some faces she doesn't look American at all, but Asian. My intention was to make her look like she's been brought up in an Asian culture but originally she'll be American. Maybe it's the hair?

Natalie Portman's facial proportions

Natalie Portmant's Facial Features