I have had a Waiver since 2013. The agents are very courteous and recognize when you are travelling with your family. Do not split up as we did try this for the same reason you are worried about (my first Waiver when the kids were young), and we were told we needed to present to the Officer with all the members of our household that are travelling. In my experience, if the agent wants to ask more questions than the standard "where are you going and staying" and "how long are you there for", they send my spouse through to wait on the other side of the sliding doors with the kids. With the Waiver this has not happened often, but it has happened. I just need to answer a few extra questions before I can go through to join my family.