My daughter has had a very high fever its been running around 103, 104.  We just found out that she has a UTI but also has alarmingly high nitrates in her urine.   She is 3 1/2.  She had an issue in September  with extreme back pain and high fevers.  At that time we were told she has a bladder and kidney infection....  Im worried this is not a normal UTI
I have studied your case. In child an UTI can cause all these symptoms. But UTI is not very common in this age, I would recommend you to get ultrasound to find out if her kidney and ureter are normal. In a disease called vesicouretral reflux, backflow of urine can cause such infection. You can consult with a pediatric surgeon in your area. Till that time you should increase her water and fruit juice intake, avoid painkillers.