Thanks from a therapist

I often am the first contact for families with a child not talking. I am a pediatric speech language pathologist of 27 years. I am now completing a masters in psychology so I can diagnoses ASD. As you know, the wait list is far too long for an evaluation. I like to listen and here from you guys what NOT to do. I never want to say the wrong thing and upset parents but it is my duty to let them know when I see something. I am open to any advice.