RB was Group Strategy Director, so it's a widening of an existing role rather than an internal promotion. Prior to this she was an advisor to the council committee that oversaw the airport in the 90s.
Rumour has it that she was put in place to 'keep an eye on' GM by the shareholders who don't like/trust him. Allegedly. I couldn't possibly comment.
The reorg seems to leave some fairly substantial gaps in the management structure at the moment, so watch this space...Olympic House must be a very interesting place to work at the moment!