Do you know how her owners handled the peeing and pooping routine?  Since you have her only temporarily, I think the best thing is to just take her outside every 2 or 3 hours, then tell her what to do and reward her when she does - like "good dog!' and maybe a treat.  She may be a little frightened with the new environment and not know exactly what is expected of her.  When our dog was a puppy she would dribble a bit when she was really excited and jumping around, but outgrew that before she was 6 months old.

Good luck!

Carol