Not so. The prosecutor WAS going to compel her to testify but could not get service on her to force her to appear for the trial.
I was a prosecutor for many years. This is how way too many of these cases turn out. The victim is afraid of becoming financially destitute, and the perp has by now apologized numerous times, bought her flowers and swore it would never happen again (but it will).
In domestic assault cases, I always made sure my cops tape recorded the victim's statement as close to the event occurring as possible. Then when she inevitably starts to backtrack, she is on tape. Further, I not only had them take pictures of the injuries at the time they occurred, I had my officers go back the next day to re-photograph those injuries. Why? The bruises rise and get darker overnight. It's a better record for trial.
It is more common for victims to back out like this than to follow through. When I subpoenaed victims, they were mad at me, not the scum that beat them up. They would be hostile, but if confronted with their recorded statement and the photos of the injuries, they had to admit the assault occurred.