Dont do anything you're not ready to do. I'm sure she is sad to and wants someone to share it with but she might not be helpful to you.
Dont bog your mind down with learning all the details of his death - instead focus on remembering his life - the good things about him. nothing good can come from those details and she may feel the need to protect herself and make herself look more innocent then she is and that could be at the expense of your son's memory.