L.S.
Do you think she could have a urinary tract infection? I know when I had one, I would be fine one minute and then need to go to the bathroom the next and it was very hard to hold so I literally had to run to the rest room or risk going on myself. My daughter had this problem a few years ago at the age of 8 too. Other symptoms included pain when peeing and blood in the urine. If she has these symptoms, you will need to take her to the doctor and get antibiotics to clear it up.