Legal Question in Family Law in Virginia

First your boyfriend needs to determine whether there is any court order

currently in effect that would require this mother to give the usual 30 day

advance notice to the court and to him as the father of her intent to move. If there is such an order, then he should file the papers necessary to have a hearing on whether she is in violation of the order and therefore should be found in contempt of court and possibly subject to sanctions.

However, in the absence of such an order, your boyfriend has the right to assemble whatever resources he can muster to find out the new address on his own for this mother absconder.