First, please decide what is her actual date of before midnight would be 8th July 2000, after midnight would be 9th July 2000.
Based on this you need to either correct the Municipality certificate (if the actual date is 8th July 2000) or correct the 10th Board certificate ) if the actual date is 9th July 2000).
Then please check the Aadhaar Card date for accuracy also.
The 10th board will correct after you get a letter from the school where she studied.If you need to go to the municpal authorities, then take the hospital certificates related to the admission and documentation at the time of her birth (discharge summary and bills) and submit an application for the change of date.
My suggestion is if she is planning to go to the US or other countries for further studies, please do everything carefully. Please check the name, spelling, initial expansion everything so that, there are no issues. Get an affidavit, if needed and keep all the documents uniform and then apply for the passport so that there would not be any issues for visa and scholarship applications in the further.