If you are doing an IUP then you can do the reservation under her number and pick it up and do your SSN for the payments. Then make sure they do not turn it on in the store and swap sims when you get home.
I literally spent over 4 hours at the Apple Store yesterday which included a 45 minute break to run back to work for a meeting and then back again.
It was an absolute cluster.
With that being said, none of that was Apple's fault but the battle between TMobile and ATT to port my number as I had to go through the process multiple times and my Apple rep had to make multiple calls which I thanked him greatly for.
He was as annoyed as me and I even offered to just pay for it outright and lets move on and he said "we can't let them win!!"
Sure enough, in hour 4 we finally got someone competent to port the numbers over, activate NEXT, and get my ip7+ black phone activated and ready to go.
It just goes to show mileage varies and the luck of the draw of which apple rep you get as this guy was an absolute superstar and he wasn't letting me leave that store without that phone. I watched so many people come and go eyeing my phone as it was the last black ip7+ in the store and reserved it just in time.
All in all, a crazy whirlwind of a day yesterday and now I am enjoying this beautiful phone and wish everyone the best at reserving theirs today. Keep checking nonstop throughout the day. I checked at 1201am, 801am, and then every 15-30 minutes randomly throughout the morning and BAM, around noonish they had a huge stock at my north texas location.