Brian.  Based on Susanita's experience and applying the rules as outlined by DanGeo should you enquire as to whether a swap would be possible as you board and be told 'no' then your daughter could stoically refuse to move when she later declares her age.  When they then relent shout 'Runaround... NOW' in your best Mike Reid accent.   ;D

https://www.youtube.com/watch?v=bKotW13Id0w

(I bet they don't see the funny side!)