She would need to return on the OLD A/P. If she comes back before the old one expires thats OK. You can't like mail her the new A/P and then have her enter on it.
Heres an explanation from murthy.com
Chat User : My AP extension and I-485 (dependent) were approved as soon as I left for India. Any advice?
Attorney Murthy : A person is allowed to attempt to enter on the AP, but there is a risk of his/her being denied entry on that AP since the AP was approved after the person had departed the U.S. If the prior AP is still valid, then one should return to the U.S. on the earlier, unexpired AP before it expires to avoid a major complication in reentering the U.S. or risk being sent back on the next flight after being put into detention - sometimes with handcuffs!
Also form Murthy.com
Posted April 16, 2004
Previously Approved Advance Parole
The USCIS stated that if a person has an advance parole and applies for a new advance parole while in the United States, s/he may travel and reenter the U.S. using the already approved advance parole. The person must return during the time period permitted under that advance parole that was approved before the person's departure. The USCIS specified that the person cannot remain abroad after the expiration of the first advance parole and then seek to enter on the second one after it is approved.
Case Example with Dates
A person has an advance parole that is valid through June 15, 2004. S/He files for a new advance parole on April 15, 2004, while in the U.S. On April 20, 2004, the person learns that s/he must travel abroad immediately. Under the USCIS advisement, the person could leave the U.S. and reenter on the first advance parole through the June 15, 2004 date. The advance parole filed on April 15, 2004 will be valid once it is adjudicated for travel from its approval through its validity date.
It would not be permissible for the person in the example above to depart the United States on April 20, 2004 and remain abroad past June 15, 2004, waiting for the second advance parole in order to reenter the U.S. The person could not have someone send him/her the April 15th advance parole in August 2004 and use it for reentry.
Select Nonimmigrant Classes
Some persons can have nonimmigrant status and an I-485 pending simultaneously, based on the doctrine of dual intent allowed under law. These classes of individuals may file for advance parole while in the U.S., leave before it is approved, and return using their proper nonimmigrant visas without abandoning the advance parole. This privilege extends to H1B, H-4, L-1, L-2, K-3, K-4, V-2 and V-3. These people must be readmitted in the nonimmigrant status without jeopardizing the pending I-485 application to adjust status.
Case Example for Reentry Using Nonimmigrant Status
A person is in the United States on H1B status. S/He also has an I-485 pending and a request for advance parole filed while in the U.S. Before the advance parole is approved, the person has to travel abroad. S/He may depart the U.S. and reenter in H1B status without abandoning the advance parole request. The advance parole is then available to use for a future trip.
Conclusion
These USCIS clarifications are helpful as these situations arise fairly frequently. It is particularly important to have this type of flexibility, in light of the timeframes for processing advance parole requests in many cases. We do remind MurthyDotCom and MurthyBulletin readers that it is necessary to be in the U.S. at the time of filing the advance parole request. It is also necessary to return to the U.S. within the time given for advance parole, without exception or delay, unless traveling on the H1B, H-4 or other nonimmigrant status. Unless a person is also eligible for entry in a nonimmigrant status that is consistent with the I-485 Application for Adjustment of Status, we often find that failure of the I-131 applicant to ensure that s/he has a valid advance parole to use for reentry can create enormous problems since waivers are rarely granted in this day and age,
