It is up to the victim when she speaks out. It should not have to be done at a time of least inconvenience to the accused.
Sexual assaults are not always easy to talk about - particularly when the victim knows that doing so will lead to media attention and woman-haters automatically assuming that she is 'obviously' telling lies.
It might be difficult to prove, but if there were witnesses, or other women who have suffered the same treatment, they can come forward and support her. If not, (and sadly this sort of thing, by its very nature usually happens so that there are no witnesses) then she risks being vilified even more. Look at the Weinstein case.
I think she has been brave, as whatever happens, her reputation will never be the same.