Yes.
Another perspective: Brother or not, are they still married, or did they divorce following his receipt of a green card? That’s a pretty sure indicator, if it happened thus, of a form of immigration fraud, a felony, but one that’s hardly ever charged due to cowardice on the part of immigration attorneys and AUSA’s. So, if it was also her brother, that multiplies the criminality - and downright filth - of the whole charade.