Author's Note:
I don't (obviously) own Marvel or any of its characters. The only thing I own here is Max and the story idea. The rating is for mild language and implied adult themes. If you don't like the story, don't read it.
Preface:
Before the Iron Man project, Tony Stark had never been the picture of virtue. A past fling from Tony's college years led to the birth of his daughter, Margaret "Max" Stark. Not knowing about his daughter until years into her life, Tony is eventually sought out by the foster system and told about his teenage daughter. Since then, he's accepted her into his life and become the Avenger known as Iron Man. Max, not an adult, is happily employed working as a liaison and assistant to her father. This entails going to meetings for him, when he's out saving the world, helping him balance his life with Iron Man's, and generally putting out fires for him.
The Sokovia Accords created a rift among the Avengers, causing Tony's team to return to Stark tower as a public image of encouragement, while Captain America and his team returned to the upstate compound. After fights, debates, and negotiations, the Accords have settled for the time being, knowing that the world is currently better with Captain America not locked up. Since tensions still run high between many of the heroes, Max takes it upon herself to be the intermediary between the teams, as well as reaching out to new heroes.
Tony sees he and his daughter as close friends, making up for the time he didn't know about her. While they may not have the best father-daughter dynamic, they get along just fine. What he doesn't realize is that their relationship changes even further when the new hero, Doctor Strange, shows up in New York. Now, Tony doesn't realize just how much Max isn't telling him...