First visit to a Psychologist
Hi, Joe -- Being a psychologist, maybe I can help. Briefly, there are no ethical reasons for the psychologist not to talk with you, since your child is 8. That can change as your child becomes an adolescent and there may also be legal statutes that come into play, too. These vary from state to state, so I can't comment on those for your state. Indeed, being the parent, it is up to you to consent to the treatment and you are completely free to ask questions, seek comments and advice, examine records, etc. You should be able to access your state's laws on your state government website (look for which agency does professional licensing in your state).
Since this is my first post here (just found this forum, looks like a great place), I can't post links, yet. However, if you google "psychologist ethics psychotherapy children", you will see several hits. The first one is to Ken Pope's website and is excellent. The second and fourth ones will from "apa" -- that's the American Psychological Association and they give some articles on the topic.
Having said the above, it can be more complicated. There might be good reasons why a child would not share many details of the session with a parent, but they might be "kid reasons" and not necessarily make a lot of sense from an adult's perspective (just cautioning you here, both as a psychologist and a parent!).
I encourage you to bring up your questions directly with the psychologist. Sounds to me like you're just trying to be a caring, responsible parent, and that's great. The psychologist should welcome that! (I do suggest that you spend a bit of time beforehand and jot a few notes to yourself about your questions, observations and concerns. Just helps you keep organized and make the most of the time.) A bit of a guiding principle: There shouldn't be anything mysterious, creepy-feeling, or secretive about counseling/psychotherapy and seeing a psychologist. He/she should be able to fully explain, in a sensible way that you understand, about both the problem areas they're seeing and what they recommend doing about it. If you're not understanding it, or have more questions, then keep asking.
Hope this helps.