Living in Beijing for 5 months!

Hi, my name is Aleeshay and my friend is going to the city this September 2014. And she needs help of international students who have already gone to Tsinghua university for any sort of Exchange program. She needs to find off campus accommodation. And being a good friend I am trying to help but I want you guys to advice me how should I help her secure a place for almost 5 months near Tsinghua. I have been advised to pay only after going to BJ. But i am not sure how many days it will take to find a room in apartment. Also my friend has two conditions for apartment sharing. First she needs to share it with only girls and second she needs a modern/newly constructed washroom. Do you think it is realistic to find a decent place for her within 2500-2700 yuan?.. And if she has to pay after personally checking the room where can she stay during her apartment search? Your word of wisdom is really appreciated. Thanks for help in advance. Cheers :)