there were three rounds of official presale - cd code, ticketmaster / axs lottery and last minute codes. anyone who didn't win the 'lottery' was put on a waitlist and prioritised for last min codes. once they built the stage they were able to add more seats and any unclaimed production friends / family etc tickets now they knew they were an acceptable w screens restricted view. they were cheaper than the rest of the tickets (57 each or something iirc) so my understanding she or a friend got off the last min waitlist once these were available.
roi has different reselling rules to the uk and rest of europe but there was fan to fan resale last year and now websites like viagogo, ticombo etc are your best bet for resale. they'll handle the purchase and then the original owner transfers details to your ticketmaster account. there's people much more familiar with how it all works so pls come over to the ts thread and ask if you need any more details! like there's more sites / bots that alert you to drops etc and ppl might have more country specfic info. we've even had tattlers selling to each other, i promise we don't bite