You take a chance with doing so . They can deny her entry into the US and send her back on the next flight.
From Murthy.com
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!
From Murthy.com
Chat User : I applied for AP. In case of emergency, can I leave for India prior to AP approval and come back to the U.S. as soon as the AP has been approved?
Attorney Murthy : As explained above, there is a risk since the CBP is allowed to deny entry to a person who attempts to enter on an AP approved after s/he already departed the U.S. The only option is for that individual to enter on the AP previously issued before that expires, to avoid being stuck at the border or being sent back on the next flight.
http://www.murthy.com/news/n_favint.html
Example from site above
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.