Its not your fault at all please dont blame yourself. She isnt blaming you please listen to her if she thought it was your fault she would say but she hasnt. If it was the other way round and she felt guilty you would probably say to her no its not your fault at all.
You would tell her to just forget about it and move on. This is what you have got to do i know that you feel guilty but you musnt she hasnt blamed you so you need to just move on and put it in the past. Feeling gulty when you have no need to be is quite common.
It often leaves us feeling bad but if you dont move on and put it behind you it could end up making things worse. Things will just keep going round in circles untill you accept that it wasnt your fault and move on.
Please take care best wishes Ian xxxxxxx