60 day rule comes from...
the fact that INS sees intent of change of status within 90 days from one non-immigrant visa to another especially in the categories of B and F visas.
In your friend\'s case , a 485 has been filed where intent of immigration has been established clearly. For your friend\'s spouse, H4 gives a basis for dual intent (i.e. immigration intent is implied in H visas). They should not listen to arm chair opinions and go ahead and file her I485 immidiately as the lawyer suggests.