Thanks AAAA, for the insight into this re/prinicpals. I just think our principals would rather not deal with it. Our head principal greets every student entering the building in the morning, and surely sees how they are dressed. It is then passed down to the teachers to deal with. I'm uncomfortable doing this, though if it were an outrageous violation, I would probably send them to the office.
The coworker who polices this really rankles me, but it's a personal reaction on my part. Today, after her confrontations of many female students this week, I did notice they were dressing more modestly. I think she told them they would be sent to the office and a message sent home about their attire.

And a bit off topic, to Pachyderm...this woman seems anything but insecure, however, I did notice that she avoided other teachers from a previous school where she worked. They, unlike the faculty at my school who are very laid back, put her thru the wringer! I work next door to her, have noon duty with her, and walk out to leave with her. Today, while leaving, I listened the whole way out about her, her family, her plans, etc. I dare not interject anything off topic in the conversation, as it goes ignored. I've learned best not to converse at all. I smell Narcissist!
Patty