Katherine Heigl's 18-Month-Old Daughter Already Using Curse Words?

Is Katherine Heigl losing her box office appeal? (Reuters)

LOS ANGELES – Katherine Heigl has never been one to deny that she has a pretty dirty mouth – but the star of the upcoming drama/comedy “Killers” has been trying to slash the swearing since she and musician husband Josh Kelley adopted their now 18-month-old daughter, Naleigh, from South Korea last year.

“My worst habit used to be smoking but I quit, so now its just cursing but I’ve curtailed that because my daughter is in a mimicking phase where she’ll repeat everything I say, and that did happen once before,” Heigl admitted to Pop Tarts.

Oh dear.

But something else we hope Naleigh doesn’t take an interest in is her mom’s new love for rifles and ranges.

SLIDESHOW: The Lovely and Talented Katherine Heigl

“I’m in the process of potentially taking some target practice lessons for my next movie ‘One for the Money.’ I’m stoked about it,” Heigl enthused. “It’s about a female bounty hunter, she’s not supposed to be good with guns but I’m still curious to know what it is like.”

And while the 31-year-old actress won’t commit herself to doing just “family friendly” films now that she’s a mother, she does intend to choose roles that have at least a little moral integrity.

“I’d hope to never do anything that I would be ashamed for her to see, but now that I’ve got a child I’m not going to only do children’s films. I love stories and opportunities to play different characters, but I won’t do anything that’s shocking and horrible in terms of playing someone totally despicable,” Heigl said. “But my work now is so about her, I don’t want to do anything that will take me away from her for too long or put her in an environment that she’s not comfortable in.  The worst part is leaving her to work, but I love to work and I love what I do. So it’s this contradiction.”

It was initially thought that Naleigh was a baby with special needs; however Heigl recently told Harper’s Bazaar that her daughter actually suffered from a heart condition that was corrected by surgery before coming to the United States in September.

“I feel like the ‘Grinch After Christmas’ where my heart is too big for my body,” she continued. “I love this child in a way I have never loved, I imagined but I never knew.”

Speaking of babies, Heigl’s “Killers” co-star Tom Selleck (who plays her father) confirmed that he and the boys are down for the third installment of the “Three Men & a Baby” franchise which was started some 23 years ago.

“Ted (Danson), Steve (Guttenberg) and I will be in it and it’s tentatively titled ‘Three Men & a Bride’ which says it all,” Selleck told us. “It will be fun to get back with Ted and Steve; they’re really great actors and great people. I just hope the script has as much heart as the first.”