I believe you can have kidney stones for a long time, I would request an ultrasound of the kidneys, that will show if you have any stones, I just had one done for the same reason, blood in the urine, but it came back negative, also if there are any other problems with the kidneys it should show up with the ultrasound, has she done anything different than usual, picking up any heavy items, fall, that might suggest a back injury, and not a kidney problem, sorry I cant be of much help, but I would definately have the ultrasound done, good luck, hope you get the help she needs