Over the last decade or so Halloween costumes have become more and more provocative. The reason is that Halloween has become a huge holiday for adults and many of the costumes which were originally designed for grown-ups have trickled down into the kids market. This leaves parents with the annoying job of having to weed out these inappropriate costumes. Here's my two cents on how best to handle these situations:
It's important to understand why your daughter is choosing a particular costume. Is she simply attracted to the sexy police woman costume because mom is a cop or does she want to wear the Hello Kitty one because her favorite color is pink? In either situation you can explain that those costumes are too grown up for her and steer her to more approppriate versions. This is much easier to do with younger children.
Where it gets tricky is if your daughter is a little older (tween or teen) and you think she is looking to be flirtatious or kiss as many boys as she can that night. In this case you have a whole other issue on your hands which requires an important conversation. Experts agree that the sexualization of young girls in our society can damage their self worth and that this is a conversation that parents should be having with their daughters throughtout the year not just on Halloween.
The conversation can happen around a program you are watching together such as Jersey Shore. You can ask questions like "What do you think of how she is dressed?" and "What impression do you think she is making on other people when she dresses like that?". This will open up a dialogue that will hopefully lead to a productive conversation. In any event, our children rely on us to set bounaries for them, so if you feel their costume is really inapporpriate then you need to get comfortable saying "you can't wear that".
Then of-course it's never a bad idea to compromise with a teen or tween as sometimes being too strict can backfire. So if the costume is not too bad but the hemline is too short, there is nothing wrong with suggesting (or insisting) she wear leggings or biker shorts under her skirt.
Happy Halloween and Good Luck :))