Kate Stark, daughter of Tony Stark, becomes a singer after the death of her father. She had a relationship with Bucky Barnes but due to the death of Tony Stark and all of the goings on of becoming a singer they drifted apart.
Max is the daughter of the one and only iron man. Her parents met when they were young and had a one night stand. She was the result. Her and her dad were very close, but what happens when her world changes forever.
I'm not really following the films. I'm using my own interpretation of events.