I do not know enough about the facts of the matter to have a meaningful opinion.

I do know what Politifact says about what the policy is:

The separations are a result of the Trump administration "policy to prosecute all adults crossing the border illegally."

"Generally, a child and an adult who arrive together at the border can be separated when border officials cannot establish the custodial relationship; when they believe the custodian may be a threat to the child; or when the custodian is being detained for prosecution."

Does this sound reasonable to you?