Trump's policy is 100% prosecution for those caught crossing illegally.
Showing up at a port of entry asking for admittance to seek asylum is not illegal, however.
Port of entry parolees or admits w/referral to removal proceedings are not resulting in family separation.
The ones subject to family separation are those who crossed illegally and only sought asylum when they got caught.
They were allowed entry without family separation. See, e.g., nypost.com/2018/05/04/doz…
Reports are that those caught crossing illegally can voluntarily return to where they came from w/o prosecution and family separation.
Asylum can be granted only to those within the United States. (This is separate from the refugee process, which is a whole different thing.)