Sorry to hear that.
But you should understand that there are many causes for this problem.. few of them could be treatable.
We need to know exact history like
how was the delivery conducted.
Post delivery baby was fine or not.
Did he/she cried immediately after birth?
Any history of prolonged infection.. or any history of meningitis
Any history of trauma.
Any similar family history.
Apart from all this we can get her brain imaging done to find any structural abnormaly.
I wish your child a happy life.
Dr Anshul MD