She's 7 weeks old, right? At 7 weeks, her "plumbing" is still mostly uncontrollable to her. She's just beginning to learn what the urge to urinate or deficate feels like, so be patient with her. My Bella finally "got" the whole pottytraining thing when she was 10 weeks old.
7 weeks is very young. It's very hard for them to control there bathroom. As they get older they can hold it longer and longer. For now, I would have her pee and poo outside every few hours or so for a week and after a few weeks of that make it 4 and so on.