When I ask myself what my inlaws could do to make it right, I find there is nothing they can do too and I am still estranged from them. I don't feel good about it, but don't want to go back for more. Have your feelings changed? If so, how did it happen, what was the process. Are you still estranged from your inlaws?
Grieving, I hope you are able to move forward cautiously. Perhaps your DIL lacked communication skills to relay her feelings in a way you were able to hear. When people are angry it comes out one way or another. If not directly then indirectly with passive aggressive remarks like you describe. That is certainly not right, but there is a reason for the anger. I don't think people generally get mad over nothing.