I'm not familiar with her but I feel this issue hits closer to home for me. I had spent many enjoyable miles on my cycle, having done work commutes and done many long distance fitness rides (50-100 miles). Biking safety is in my blood. But biking in insane urban traffic areas like London is often at cross-purposes with safety. sooner or later something bad will happen.
If the amount of bicycle trips increases, the amount of car trips increases..and add to that the amount of foreign drivers increases...and the roadways are designed from prior to the invention of cars, you have the worst possible combination.
Appropriately is concern for any cyclist not wearing a safety helmet. I have no idea if she did or if it would have mattered. However, in my case, my life and (what's left of) my brains was most likely saved due to my wearing a helmet.
I cycled around for a good decade in the dangerous urban area of Boston-Cambridge MA and its suburbs and outlying areas. Furthermore, my then-wife at the time worked as a trauma nurse in famous Boston head-injury clinic. She saw the bad end of many motorcycle and biking accidents. She saw first-hand what the difference was with wearing a helmet.
Furthermore, I picked up a friend at a hospital after a week of recovering from his fall from a biking accident. Mild concussion and loss of teeth. He wore his helmet. Docs said he'd not have been nearly as lucky if he wore no helmet.
London urban area seems to be far less safe than ever for cyclists.
How very sad that is.