How about these people recognize that they're trying to commit a crime - entering the country illegally - and then, if they want to avoid incarceration, perhaps try not committing said crime?
All of this "protest and send money" stuff undermines the legitimate rule of law. Family separation is bad, but it happens all the time when people commit crimes within the country and lose their children by virtue of being deemed unfit to parent because of criminal actions.
Why should an illegal alien be treated any differently on that front?
These children are being used as emotional manipulation to exacerbate a problem that's already pretty egregious.