I believe her.
What would she gain by lying? It must be completely humiliating to have to go public with what happened,and have people judging and doubting her.
We all know that the police have form for going after women that they perceive to have put them in a bad light,why would she invite that sort of attention?
I've had to have a talk with my teenage daughters about what to do if stopped by the police. It's not something that I thought that,I as a law-abiding,middle class, white woman would ever have to do. But here we are.