Earlier quoted context omitted.
Yes, when you phrase something without context it's easy to make it sound insane. When you include the context where they need to verify that it's not human trafficking and that children are separated from their parents every day when the parents are arrested for any other crime, it's not quite as insane.
I believe you are the one lacking context. I'll assume your are not being intentionally malicious and are just naive. Abuse is almost certainly occurs in the presence of power structures with severe disparity. Children are being placed in the custody of people who lack appropriate training, background checks and supervision. Children can not defend themselves and they are separated from the people who do protect them…
Apparently you have never heard of what happens to every child initially separated from parents arrested for a felony. I suggest you look into the foster system in the US to see the horrors.
The treatment at the children sucks, but it has nothing to do with Trump. It's entirely based on children in the US receiving shitty treatment under 'the system' in the US.