The same way USA used to be called "the melting pot" because so many people from so many different parts of the world were there, its the same for Argentina. From native americans (the badly na5b4med "indians"), to people from almost every part of the world came to Argentina to live.
On topic: there is an interview of her with Rolando Hanglin (radio personality/journalist).

I have "Argentinian" relatives that are Jewish lol. There are tons of Europeans in Argentina - I believe Buenos Aires has a huge Italian Festival every year. So she may just be of European descent rather than South American native descent

Her father was born in Argentina. I don't know where his bloodline started. People have been looking for a better life in the new world for over five hundred years. There are A lot of Germans and other Europeans in Argentina as well.
"This is the worst kind of discrimination! The kind against me!"

And she looks like the argentinean actress Eugenia Tobal.

She sounds 100% portea
Come on, there's no reason to insult her!

really she doesn't seem argentine or spanish

Well, not at first, but after a few visits Viggo Mortensen came up with a very good Argentine accent. Not nearly as good as Sonya's though! She sounds 100% portea

• 'You're a
  teacher
  ?
• Part-time.

I heard her today on some interview about FlashForward and I came here to confirm that shes argentinian and omg I cant believe she is english.
I never heard before a british or american speaking like a real argentinian.

Didn't know that, so cool!

• 'You're a
  teacher
  ?
• Part-time.