"I do like change. That's the one thing exciting about me," says Heigl, 31. "I like going on location for films. I like new characters. I change my look a lot. But roller coasters are as adventurous as I get."
It's a different story for Heigl's character Jen in Killers, in theaters Friday. The romantic comedy/action thriller stars Ashton Kutcher as a trained killer who falls for a normal gal played by Heigl.
"Jen is kind of dorky," says Heigl, who is currently a brunette but is a blonde in the film. "But she doesn't know she's dorky. She has a moment when she tries to be sophisticated, and then she gives up."
When it came to starting a family, Heigl did just the opposite. She stayed the course through the "nail-biting" process of adopting a baby.
Heigl says her perspective has changed "in a good way" since September, when she and her husband adopted Naleigh (pronounced Nee-lee), a 10-month-old girl from South Korea.
"I can't imagine my life without Naleigh or not being her mother," Heigl says.
The past six months have been life-altering, Heigl says, but "I still laugh at the same things and get angry at the same things. I'm a sappy mom now. I didn't think I would be. I thought I'd be a cool mom who keeps everything in perspective."
Heigl might be sentimental, but censored, she isn't.
"I've tried to keep my mouth closed for a minute," Heigl says with a wry smile," and I can't. At one point I got so paranoid and afraid, and I was qualifying everything I said and apologizing for everything. I realized it was ridiculous."
(Heigl famously spoke out against Grey's castmate Isaiah Washington for using a slur against co-star T. R. Knight. She also withdrew her name from consideration for a 2008 Emmy, saying, "I did not feel I was given the material this season to warrant a nomination.")
Now, Heigl says she's trying to "stay grounded and real. Sometimes I say things that are stupid, but I'm trying to be honest and relate to other people," she says. "Occasionally things get taken out of context. But that's life. I like to encourage other people to not feel that they have to say whatever the publicist tells them to say."
Heigl says she misses her Grey's friends and her character, Izzie Stevens, but she feels she made the right choice to move on.
"I felt very protective of Izzie. I really loved her. I felt she was an admirable woman who certainly made mistakes. But I was starting to not like her, and that bothered me," she says.
Leaving Grey's enabled her to grow closer to Naleigh. "I can't cultivate a relationship with my child if it's between takes. I tried that on a movie and realized, 'This is not going to work.' It will work some of the year, but not 12 months a year," she says.
Meanwhile, Heigl isn't ruling out more kids — biological or adopted.
"Maybe we'll have four or five kids. We'll see how two go. Two could throw me right over the edge. We've talked about biological children, and we haven't ruled it out. But I would like to adopt again. It's a little bit hard for me. If I have a biological child, is there a child now who will go without a mom? But I can't take them all."
In July, Heigl starts filming One for the Money, an adaptation of the first of Janet Evanovich's Stephanie Plum novels. Until then, she'll enjoy hanging out at home.
"Josh and I have a fantastic group of friends who we took a long time to cultivate and who hang out at my pool almost every weekend. We laugh. The boys play football, and we grill. We lead a suburban normal life in Los Angeles."
