Three point turn collision, who is liable?

Hi there! I had a very minor car accident outside my house yesterday, but both parties are blaming the other. Can someone give me some advice on who the insurance company are going to say is at fault?
I was parked at the side of the road and am going to make a three point turn to face the other direction. As I am about to take off a lady pulls up behind me. I indicate and pull out at a 90 degree angle (or as close as is possible) but as I reverse the woman has pulled/ is pulling into the space I've barely vacated and I bump her front wing. She claims that she thought I was just going to pull out and I have reversed into her. I say that she has moved into my space as I'm reversing, and I was clearly making a three point turn. I also have eyewitnesses that say it is impossible to think that I was doing anything other than a three point turn as I pulled out at a ninety degree angle.
Who will the insurance company say is at fault as the woman was very shrewd and came and accused me of about fifty things immediately? I have no damage to my car and seven years no claims, and so wondered if it would be worth settling it a different way.
Thanks