Can Parents View the Content of IMessage Texts Using the Companion?

Just want to clear up how the new Companion app works. I’m not sure if my parents can view the exact texts I send to who I send them or when I send them when using a third party messenger like iMessage. I would also like to know if they do check on my messages will I be notified of it like when they check my location or am I just left in the dark. Thanks