Graham, 49, told the January issue of Good Housekeeping that the pair initially kept their relationship in the friend zone, but things eventually evolved.
"We couldn't stop talking," Graham said of Krause, 51. "Not about ourselves, but about the world and books and family.
"Once we got together, there was no game play[ing]," the "Gilmore Girls" star continued. "It was like, You like me, and I like you. It gave me an understanding of life: This is how things happen, and it's completely random."
She added of her relationship with Krause now: "It's not a big, loud life. We have a lot of neighbors, people come by, we're with Peter's son a lot and we keep it small."
The same could be said for how Graham approached her career. When she began acting after college, she decided to pursue it one small role at a time -- starting with a commercial, then a play and eventually moving to Los Angeles with friend Connie Britton, whom she met in acting class. And while it may seem random that she would end up being best known for playing two similarly unconventional single moms of teens, Graham knows what she's best at.
"There are things that I’m good at and there are things that are just not for me," she told Good Housekeeping. "I’m not gonna play a cop, I’m not gonna play a doctor ... and that’s OK. I’d rather be in [roles] that are really verbal and smart and funny. As Diane Keaton said to me, 'Funny doesn’t age.'"
That said, Graham said she relates more to Lorelai Gilmore than she does Sarah Braverman, her character in "Parenthood."
"I mean, I speak quickly more in attitude and just in athleticism of what that work is and was for me, as an actor, that’s a place I feel really comfortable and exhilarated, so, in that way I guess I relate a little more to that world and that language," she said of Lorelai Gilmore, a character she recently reprised in the four-part Netflix revival.
Along the way, she has discovered a hidden talent for writing, having just released her memoir "Talking as Fast as I Can" and completed her second novel (her first came out in 2014).
"One day in my trailer in 'Parenthood' I looked up and I had the afternoon, and it just kind of occurred as a way to be creative and but not have to be part of any other structure. It was kind of a revelation that I could just do something on my own and the fact that it has now given me other work is like icing. I just did it for fun."