VISA Extention

My girl friend is from the Phillipines and therefore Philipina. She has a Schengenstater Visa she received through the Swedish Embassy. She entered through Amsterdam before going onto Stockholm where she spent the night. Her Visa is stampted 13 Aug 09 and is a type C valid for only 7 days valid through 20 Aug 09. I am an American working in Germany for the US Government and she is residing with me in Germany. OUR QUESTION IS: HOW CAN WE GET HER VISA EXTENDED AND UNDERSTAND THE MAXIMUM TIME ALLOWED IN 180 DAYS IS 90 DAYS. WHAT EXACTLY DO WE HAVE TO DO TO GET IT EXTENDED BEFORE IT EXPIRES? THANK YOU!!!!!

Turn to the nearest Swedish consulate; since Sweden was the issuing country, afaik they are the only ones that can extend it.

I have to warn you that there is a fair chance the extension will not be granted: European immigration authorities are rather harsh towards citizens of the Philippines. Also, the Swedish consulate will probably want to know why your gf hasn't applied for a visa with the German authorities, since Sweden apparently wasn't the point of entry, nor the main destination of the trip.