hi, welcome to health care magic,
PUJ o is a congenital obstruction of the pelvis ureter
junction.It occurs during foetal development, the treatment depends on the symptoms and the function of the diseased kidney
In your daughters case, the kidney is infected and the function is also very poor, there is a small chance that the kidney will improve over time.
As the right kidney is functioning well, the left kidney can be treated either by surgery to correct the problem or to remove the poorly functioning kidney as it may keep causing problems in the future.
this has to be discussed well with your treating urologist
and follow accordingly.
I wish her a speedy recovery