"I would daydream about it all the time," Mary-Louise told the mag, in her first interview on the subject. "I thought about the fact that there were children who didn't have anything, and I felt like I could help. It was something that weighed on me."
The star adopted Caroline in August 2007, when she ventured to Africa with the organization Worldwide Orphans. She was already mom to William Atticus, now 5, her son with ex Billy Crudup – who reportedly left her during her pregnancy for actress Claire Danes. And the single star said sometimes she wishes she had a partner to share parenthood with.
"Sometimes, sure. I wish I could give them everything that was a perfect little family paradigm," she said. "But I can't. Honestly, I feel like that doesn't even exist, or at least I try to tell myself that when I am feeling bad about not providing it."
Her adoption, she added, wasn't just to fill out the family.
"It was something I did for the world and for my son and then for me," she said. "And when I say the world, I also mean my daughter. Once I knew her, she became part of that. But it's hard raising two kids as a single person. It's a lot of pressure."
Still, she seems happy with her motherhood – and hanging out with her kids.
"Sometimes I just look at them and I think, 'You are the two coolest people I have ever met,'" Mary-Louise said. "I was getting ready to come [out] tonight and my son came up to my trailer and said, 'Where are you going, my beauty?' I hear that, and I don't really need anything else."
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