while my girl bagged up she had clear fluid. and the day she foaled it was a white color so when the fluid is white you'll know she is ready!
As for the pee...She could be a little dehydrated. She could just have too many hormones in her system or it might just be normal pee that you're obsessing over. Is she drinking at least one full bucket of water a day? Preferably you want them drinking a lot when they are pregnant so make sure she always has nice fresh water.