In ureteral duplication the upper pole ureter often inserts ectopically into the bladder or surrounding tissues, and it can be obstructed. The lower pole ureter can have reflux, which can contribute to incomplete bladder emptying. (Of course either can have reflux or obstruction but the above is the more common scenario). If she has pain from the obstruction, if the obstructed pole is infected, or if she has difficult to control hypertension, then I would consider surgery; however, I would hesitate to subject her to the risks of surgery and anesthesia otherwise.