A relative of mine just had a baby, and her mom came from out-of country to meet her grandchild and help mom and dad in those first crazy weeks with a newborn.
But when she told CBP that she was "coming to help her daughter with the new baby" she got detailed and questioned for 2 hours. Eventually they let her through but they were really trying to pin her coming to work illegally on a tourism visa.
If you or a loved one are in a similar situation, just say you're "visiting family". Apparently it's a legal gray area in this shithole to help your child take care of a newborn.
Per that last bit, I'm guessing they never had a lawyer present. Would make any of those fabricated statements null and void, if the constitution meant anything.