As far as my own knowledge:

She need to bring her passport,id's and credit Card. She can go to the airport,where the visa department ( i assume). Coz the last time i was there.The guy told me.If you would like to extend your visa.You can come here(airport) or give us a call.

But anyway, the best thin'you can do is, call the visa section or here is the website below. You can read or do the re-search about this matter.

http://www.moi.gov.qa/site/english/index.html

GoodLuck!

I miss Qatar not just the place but also my friends.