Your daughter is experiencing something that is extremely typical post-Nissen surgery. The esophagus is a "dumb organ" and it interprets all pain as reflux. Also, your daughter's wrap is and will become more and more swollen over the first two weeks post-op. Because of that, food can be held back at the wrap site, and iritate the esophagus--mimicing reflux.
When I had that experience, my surgeon told me that "anything is possible", and there could, indeed be some reflux slipping by the swollen and misshapen wrap. Often surgeons suggest that their patients continue with their PPIs to help keep their recovery more comfortable.
Here is a link to my early recovery journal. Hopefully it'll give you an idea of another person's early recovery.
Glad you've joined the forum. Be sure to continue to ask questions as they come up, and we will do our best to answer them. This is a great place for support, so stick around!
Very best wishes,
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”