It's damn near impossible. Given the amount of pushback women get from the system, something should be done to help. Suffering systematic abuse then having a system that basically says, "You wanted it," must be extremely draining.

Our system is only slightly above ones that require a male relative to have witnessed the assault before accepting that it wasn't the woman who committed a crime.

The likelihood of successfully prosecuting a crime does not affect the reality of whether or not that crime occurred.

You probably can't. That affects whether or not you can reasonably pursue it, but doesn't change the objective fact of whether or not it was consensual.