Thank you for your question. I look forward to working with you to provide you the information you are seeking for educational purposes only.
If he is making inappropriate sexual comments to her, it is first of all child abuse
and you need to inform the child protection authorities. It is also deemed harassment
and grounds for you to sue the counselor and the school for this harassment.
As far as a civil rights violation, Title
IX of the Civil Rights Act prevents teachers from sexually harassing students. So him harassing her based on her sex, would also violate her rights under Title IX.
As far as the ACLU, they take cases only that are "sexy" and "big money" and "front page media" cases for them. So, you can contact the CT ACLU at http://www.acluct.org/contact-us/.
However, even if the ACLU does not agree to assist, which is a good chance, you should not let this go and you need to report this to the authorities for this teacher preying on underage students.