OK. Under those circumstances she woould have to take the bulk if not all the liability. Except that one thing still bothers me. Why was there even room for her to pass? In a drop off like you describe I don't understand why there was room to pass on the right. My daughter's elementary school had something similar to what you describe. It was a circular driveway. Cars pulled into the driveway, ALONG THE RIGHT EDGE, discharged there passengers and drove forward to exit the other end. I just can't imagine why there would even be room for a vehicle to pass on the right. That makes absolutely no sense to me. And I believe that also bothers my colleagues.
I'm sorry but your attitude here leaves a lot to be desired. Everyone on this site VOLUNTEERS their time and expertise to help others. No one has given a "biased" opinion. They have given you the benefit of their knowledge and experience based on the information you posted. I can't find any bias or fault in their answers. And I think it is unfair and uncalled for of you to put down others simply because their assessment of the what you told them doesn't mesh with yours.
But here's the bottomline. My suspicion is that the insurance carriers are going to take the easy way out and just go 50-50. But, in doing so, neither of you will be out of pocket. If that happens and you don't like it, then you are going to have to take one or both the carriers to court. If you can prove that she had no business passing you on the right ad did so in violation of traffic patterns and safety warnings, then you should have a strong case.
Finally, I caution you against any further displays of attitude. If you don't like the advice given then ignore it. If you believe the advice is based on incorrect assumptions then point out where those assumptions are incorrect without putting down the poster. But any further disparaging remarks will be removed.