Time are changing because of the like of Rachael Blackmore, Nina Carberry, Katie Walsh, Holly Doyle, Nicola Curry etc. They are good riders who are down to earth and get the job done. Bryony Frost is setting that campaign back. I know the public like her banging on about her special pegasus and her pet pony etc. But in racing we quite simply see that as annoying and childish. Something a 12yo would say who had just won their first jump off. Not a professional jockey.
As for making statistical judgements on the fragility of women - there's no point doing this on the back of a fag packet. To understand if injury rates really are higher/more serious you'd need to work through the quality of horses they were riding, their previous history for URs or falling and also consider the comparative fitness element of the number of rides that the jockey is regularly getting.
Total credit to RB though - I have a huge amount of admiration for what she has achieved and think she's done it all in a very classy way.