Hi Paige,
Welcome! You're in a place of people who really understand. I hope you're finding some good resources along the way.
I'm an Adult Child of an Alcoholic. Speaking from the children's point of view: yes, they know, and they are developing their own unhealthy protection mechanisms, as Thumper so aptly described. It takes a lifetime of un-doing it. I will tell you that the hardest part of my recovery has been in forgiving my mother, the sober parent, for not taking care of us sooner. We have a good relationship now, but it has taken 20 years to get it there.