Hey there,
I found the below information for you, i hope it helps. Seems like your piggie may just have a high level of calcium in her pee.
URINE NORMAL:
Urine may be clear to cloudy in color. Calcium compounds in the urine cause this cloudiness. Normal urine is
not gritty in texture. Dried urine may leave powdery white calcium compounds. Very young guinea pigs often have an orange or brown tint to their urine. Urine sometimes changes to an orange color on standing (this may be the oxidation of porphyrins in the urine).
NOT NORMAL:
Gritty compounds: may indicate sludge in the bladder. Strong smelling urine may be a sign of dehydration or infection. The gritty deposits are sometimes called sludge, which feels coarse and sandy. Powdery deposits are normal. Rub the deposits between your fingers to determine if they are powdery or gritty.
Blood in urine is not normal and may be due to a urinary tract infection, bladder stones, or (in females) reproductive problems like pyometra (an infection of the lining of the uterus).
Incontinence is not normal. Your guinea pig should be relatively dry. If its fur is constantly wet and/or there is an odor, be sure to have your pet checked out for a urinary tract infection or other problem.
TIP: To check for sludge, line the cage with dark colored towels. To check for blood, use light colored towels.