The "Fire with Fire" star wants to focus on "making the world a better place" when she eventually settles down to start a family, reported Latina magazine.
"I won't be able to act anymore. I'll just be focused on trying to make the world a better place for my baby," she said.
The 33-year-old actress also admitted she used to go to school in her pyjamas and confesses her casual style hasn't evolved much since those days.
"I didn't brush my hair; I wore platform flip-flops and Converse because I had a height complex. I would roll in wearing my pyjamas, just in the nick of time before class started. And that's still me."
Dawson's relationship with 55-year-old Boyle was revealed earlier this month, with the actress, who met the filmmaker on the set of his latest film "Trance", even in attendance at the London 2012 Olympics opening ceremony, which the director masterminded.
Dawson took to her twitter account to share her joy about attending the spectacular event with her followers.
"What an amazing honour to witness the Opening Ceremony of the London 2012 Olympics!"