Something to remember when talking about the separation of children from their parents is that this happens in the US every single day. Social service agencies do it everyday, mostly to people of color, with blacks bearing the brunt.
We tend to pay attention to something that happens in bulk, and forget that the same quantity of people are affected, but one at the time. We are horrified when a plane falls, but the equivalent of a full jumbo jet is how many children die of starvation every day. When it's concentrated and at the same time, we are more likely to be horrified than when it happens slowly and over time.
And it's a long this lines that we are more horrified about the Holocaust than slavery. One happened swiftly, whereas the other one simmered over centuries. The best way to "see" this is to compare how many movies and documentaries there are about WWII and how many about slavery. And in many movies, slavery is just a prop; say Gone with the Wind. There are very few movies and shows about the lives and suffering of slaves in plantations.
Going back to the plane fall and starvation, we also have oodles of movies about plane crashes, but none (as far as I know) about the people dying of starvation.
So please, when you feel indignant about what's happening at the border, and you desire to do something about it, you need to keep in mind that this happens in the US every single day. And we need to be as indignant, protest, have rallies and do something about it too. Otherwise, we behave in a racist manner in which only some children and their families matter, whereas others do not.