Oh, and one more thing, healthmyths.
You tell your daughter-in-law that life is way, way, way harder for an illegal immigrant than it is for her. But they were still desperate enough to come to America anyway.
And you tell her that whatever path to citizenship they will eventually get will be just as difficult, if not way more difficult, than it was for her.
You be sure and tell her that, mm-kay?
Also, ask her why no group of permanent immigrants (family-based and employment-based) from a single country can exceed 7% of the total amount of people immigrating to the United States in a single year, even if they are coming from right next door.