Given the predilections of the TSA clerks to prevaricate and fantasize, I don't believe there's anything "normal" about the process.

Sometimes nothing untoward will happen. Sometimes you'll get one of the TSA's many "bad apples" who will simply make up "regulations" out of whole cloth to do whatever it is they're trying to do - whether to separate the child from the adults so they can grope with impunity, separate the passenger from their carry-on so that stuff can be stolen by the TSA clerks at the checkpoint, or whatever else they want to do.

Best of luck.