Poor girl. What tragic news.
I’ve ridden a fair few descents like that on a fixie with only a front brake, and at times I’d wonder what might happen if it ever failed. You can easily reach 40mph on a fairly steep hill without braking, and slowing down without brakes must be next to impossible. Jumping off or purposefully crashing can’t be an easy thing to do – it goes against natural instincts – and there probably isn’t a lot of time to react. Those roads aren’t the most friendly places to do it either – lots of gravel and roadside rocks etc. One thing I learnt from my motorcycling days is that it’s often possible to take corners faster than you’d think possible so long as you think positively, but that’s always easier said than done, and in any case probably of no help when you’re absolutely petrified and having to attempt a corner at a runaway speed.
I was on that first Bealach na Ba ride, and descending as the ambulance reached the crashed rider. I believe he panicked at the corner, tried to brake too hard, and went straight on without cornering.