No-Maj-born witches and wizards are integrated into Wizarding society. No mention is made of their families, but presumably they're separated from them at an early age and the families obliviated to remove any knowledge of Wizardkind.
Per Pottermore:
Pure-blood families, who were well-informed through wizarding newspapers about the activities of both Puritans and Scourers, rarely left for America. This meant a far higher percentage of No-Maj-born witches and wizards in the New World than elsewhere.
While these witches and wizards often went on to marry and found their own all-magical families, the pure-blood ideology that has dogged much of Europe’s magical history has gained far less traction in America.
We're also told that the split between Wizard and No-Maj society is absolute, with zero exceptions.
Dorcus’s indiscretions led to the introduction of Rappaport’s Law. Rappaport’s Law enforced strict segregation between the No-Maj and wizarding communities.
Wizards were no longer allowed to befriend or marry No-Majs. Penalties for fraternising with No-Majs were harsh. Communication with No-Majs was limited to that necessary to perform daily activities.
Again, this presumably extends to family members.