Life insurance pay out

my wife just passed away she completed her life insurance Papers years ago. At the time she was single and left 50% to her father and 50% to her mother. When we got together and bought a house we both changed our beneficiaries on our life insurance to each other, Or So We Thought. Come to find out hers never got processed by the company and now I am having problems with her family. Her father passed away 12 years ago so he would not get his 50%. Would I be entitled to that since I am the next of kin or does her family get that part as well. Her mother says she is going to give me all the money because that's what she knew what her daughter wanted but her brother is trying to talk her out of that and keep it all. Where would the money go? Me or her mother ( in this case her brother)