Oh, no, magenta3603565. What a poor turn for your carefully planned birthday surprise -- I'm so sorry. It's an incredible gift, and a huge upgrade from her existing device. She sounds like an awesome kiddo!
The automated messages do go to the line being upgraded rather than the primary account holder -- this is by design, as we have many customers who are on family plans that don't reside in the same home or area as the other members of their family, and this way the person who needs to pick the device up or make sure to snag it from the porch gets the notifications to keep them up to date.
That said, we do have options to switch the messages to an alternate line. It's a shame that we didn't discuss this with you, this time of year it's a best practice to bring this up by default as we have many customers ordering gifts for others as surprises. It sounds like we could do a better job of making sure we're bearing that in mind and offering the option to switch the messaging to another line.
I know that we can't change what's happened here, but we do appreciate the time you've taken to share your experience with our community so that we can forward this feedback. I hope your daughter loves her new phone, despite the missing surprise element, and that she has a fantastic birthday.