The only issue would be the delivery of her visa and documents back to her once it has been processed.
They cannot be returned to a different address, so she will need to make sure that on the application form and on her return shipping label, she puts the correspondence address where she will physically be located at the time of the decision, in order for her passport and documents to be delivered back to her... as she may need to sign for them on delivery.
Original documents are usually returned within about 1-3 days of the decision made email, depending on how long it takes them to get the package ready to be mailed, and for it to be picked up by the courier.
So, if she definitely knows she will be moving down to Texas while the visa is being processed, then she can use her parents' address for the return of documents. If she's not sure what she's going to do though, then I would have her use her current New Mexico address and she should stay there until the visa has been processed and returned to her at that address.
