Can you make two separate claims on the same part?

My son just rear ended someone. He was breaking to a stop the road was icy and he slide in to her putting a crack in her bumper. She told my son and the police officer that a second larger crack that was in her bumper had occurred the previous week by someone else and she had already been paid by their insurance and was planning on getting the bumper fixed anyway. She later told me the same story on the phone when I called her. Now her dad has called me and said no she wasn't going to get it fixed under the first claim (is just keeping that money) but now with a second crack wants to get it fixed so wants to claim it under our insurance or have us pay for it. Is that legal? It seems they just want to profit from this.