Do you know if when she actually goes to add the line, if she picks unlimited everything will that cause problems with activation? I told her to pick payg texts for sure, but not sure of the minutes. Then when she activates the phone she can switch the plan to UL minutes and texts.
I can't say for sure, but part of the reason I added the line (in addition to getting the subsidized iPhone that let me sell off my T-Mobile version) was to add the $5 text option that is only available at inception of a line. I had no problems selecting 450 minutes, 250 texts, and iPhone Unlimited Data. It activated just fine yesterday.