Hi, Thank you for posting your query in healthcaremagic.com and giving us this opportunity to clarify your doubts. Well, I really do not follow what you mean by saying that her urinary tract was not found ???. This is unlikely. Well, there must be some developmental malformations in her urinary system since birth, which has gradually progressed to shrink the size of one of the kidneys. I will need a lot more information to help me in the diagnosis. Anyways, I would recommend you to see a pediatric urologist, who would be well versed with all the congenital malformations of the urinary system. You might also need to do a creatinine level, to look for the efficacy of kidney function. Does she have any symptoms related to the urinary system like recurrent Urinary tract infections, Vesico-ureteric reflux disease, etc. She can have an association with the above mentioned urinary system abnormalities too. As mentioned, I would recommend you to visit your pediatric urologist and take his opinion. I hope I have helped you clarify your doubts and helped you make a decision. Take care and stay healthy.