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Kristin Davis (search) is surprised as anyone that she's gone from "Sex and the City (search)" to playing moms in the movies. Davis plays a mother in two new family films: "The Adventures of Sharkboy and Lavagirl in 3-D (search)," and a remake of "The Shaggy Dog (search)."

Davis says it was difficult knowing which roles to choose after "Sex and the City" ended its successful six-year run on HBO last year.

"It's crazy hard, our business," she told reporters recently. "You make the best decision you can, but sometimes it doesn't make sense from the outside world 'cause it's just not easy."

On "Sex and the City," Davis played Charlotte, the prim, wide-eyed optimist among a group of four independent Manhattan friends. On the show she and her husband try unsuccessfully to have children of their own, but in the series finale they find out they're adopting a baby from China.

Still, Davis wasn't expecting to play a mother in her first major film roles. In "Sharkboy and Lavagirl," which opens Friday, she and David Arquette play the parents of a boy who dreams up elaborate fantasies. The movie was directed by Robert Rodriguez ("El Mariachi," the "Spy Kids" movies). In Disney's "The Shaggy Dog," Davis will play opposite Tim Allen in a remake of the 1959 Disney film, in which a boy changes into a sheepdog. A sequel, "The Shaggy D.A.," came out in 1976.

"I had already started doing "Shaggy Dog" for Disney before Robert's movie, and I was amazed when they offered me that part, because I didn't think the first thing out of 'Sex and the City' would be a mom," Davis said.

Davis said now that "Sex and the City" is over, she's glad not to be fodder for the tabloids anymore.

"The whole insane magazine-tabloid thing that's happening now, when there's a gazillion hundred of them, it's just out of control," she said. "A lot of it is not true, so all those people who are buying those magazines are reading stuff that are total made-up lies."