I just wanted to know if any school of thought has proof that the mawlid was celebrated by the ahlul bayt and/or if the prophet celebrated anyone's birthday while he was alive. I am not interested in any opinion of any school of thought without proof that the ahlul bayt celebrated mawlid or without proof that the prophet celebrated birthdays of his family members.
You can find better answer from here.
I'm quoting a portion of the fatwa below:
Celebrating Eid Meelad al-nabi (the birthday of the Prophet) is not proved by Hadith and Quran. The companions of the holy Prophet Muhammad (صلى الله عليه وسلم) who held great respect and love for holy Prophet Muhammad (صلى الله عليه وسلم), they never celebrated Eid Meelad. It is the invention of Christians which was invented following six hundred years after the holy Prophet Muhammad (صلى الله عليه وسلم). We are not asked to celebrate the birthday or death-day of anyone. This day should be spent like other days.
Remember in Dua.