If sticker shock doesn’t get you, the sexy nurse, the naughty school girl or the she-devil might, if you’re out shopping for Halloween costumes with your tween.

Finding the right costume for her pre-teen has become a hellish experience, a friend recently confided.

Walking through the stores with her 12½-year-old and 8-year-old girls, she came face to face with the tramps—full-chested models wearing plunging necklines and shorts that exposed long legs in six-inch heels. They were plastered on the wall in full color.

“I was utterly embarrassed at what some of the costumes look like,” my friend said. “Plus, the expense is outrageous.”

For tweens—8- to 12-year-olds—who have suddenly grown into adult sizes, Halloween presents dangerous new territory. Plus, vampy costumes seem to be increasingly marketed to younger children.

Although my friend’s tween actually wasn’t interested in the “trampy” costumes, she was at an awkward age for costumes, where a gap in sizing narrowed her options. She knew she didn’t want a sexy costume, but she also didn’t want something that was Hello Kitty.

“There were no good choices between kids and young teenagers—everything was really low-cut,” my friend said. “In past years, we’ve just pulled stuff out of the closets, but this year, she was invited to a party, so I decided to go ahead and get her a costume.”

Tweens often aren’t aware of the signals they’re sending dressed in sexy, grown-up costumes, said another friend, who says she tells her pre-teen to think about the messages clothes may send.

“You want to attract boys that are respectful of you,” she tells her daughter. “You may inadvertently be attracting a different person.”

As parents, we need to make our children aware of the dangers it might pose, she says. “Someone might get the wrong impression.”

A quick review of Internet message boards reveals that, in dressing rooms across the nation, many parents are battling the issue of inappropriate dress with their pre-teens.

Tweens aren’t interested in looking sexy as much as they’re trying to look like other pre-teens so as to belong to the group, says Nancy Rue, an author who writes self-help books for tweens and teen girls to help them through adolescence.

“There’s nothing wrong with wanting to dress like everyone else, but it definitely provides a teachable moment for moms and for dads when their daughter comes home and says everybody else is dressing up like French maids for Halloween.”

Faced with such a situation, she offers these tips to parents:

• Sit down and have a heart-to-heart with your daughter about why they want that particular look. Ask them, “Do you think everyone else is going to show up as a sex kitten, or have you really even thought about it?” Rather than lecture, it’s a good time to chat about the reasons. You might mention that it really isn’t kids who have established this trend, but adults in marketing, Rue says.

• Suggest that not everybody is going to be baring it all, despite what they may have heard in the girls’ restroom.

• Establish some guidelines—such as, how short a hemline should be—before you go shopping or before you go into the attic to start pulling things out, so you don’t have an argument in the costume aisle. This way, your tween can make choices within those boundaries.

Still Rue admits there’s always a tween who will want to push the envelope: “No matter what, she’ll always want to go an inch shorter, an inch lower, and that’s a great time for her to learn the meaning of the word, ‘enough.’ You are her parents after all, so love her enough to let her hate you for an hour or two. She’s going to get over it.”

For the rest of tweens, there’s some middle ground out there. In my friend’s case, her daughter settled on a bumblebee costume, and they both flew out of the store happy.