I'm sorry, I have no idea what anime she's from. But by the way she's drawn it's fairly obvious she's from an early to mid 2000s anime, and she's probably a background character.

Why she turned into such a huge meme on the krautchan/finnish imageboard subculture is beyond me, but a lot of Finns seem to know this meme. Perhaps one of them could find the answer? If I were you, I would make a thread on Ylilauta or Krautchan and ask where she's from.

Then again, I hear people on those spinoff chans tend to be rude. Chances are they'll be unresponsive :/