People who recieve good sex and relationship education usually have better sexual knowledge, better sexual health and reduced vulnerability to sexual abuse.
Mencap - Lo of easy to follow girls dating website, including a FAQ section for young people, and for anyone supporting someone with a learning disability. Download - Sexuality and Relationships Resource by Mencap.
Brook - A free and confidential services about sex and relationships. Their website keeps an up to date and comprehensive list of resources suitable for parents, teachers and young people.
If your school is ed up and working towards improving RSE they will be able to parental awareness sessions.