FlyerTalk Evangelist and Ambassador: The British Airways Club
Join Date: Jun 2008
Location: Somewhere between 0 and 13,000 metres high
Programs: AF/KL Life Plat, BA GGL+GfL, ALL Diam, Hilton Diam, Marriott Gold, blablablah, etc
Posts: 33,167
Easiest would be to offer a swap to her neighbour once onboard. I would tell the crew and ask them to approach the neighbours to see if one would accept the swap.
However, do keep an eye on availability, F award space could always show up and if you have the miles, you may be able to change your partner's booking so he/she can join you instead?