Clarity on insurance act and succession acts

My brother who was a converted Christian passed away due to second wave of covid last year. He left his parents and spouse with no children. He made our parents as nominee for every case. Now for his terminal benefits, a family member certificate issued by Andhra Pradesh Government was produced to the company. (In Andhra Pradesh, FMC is considered as legal heir certificate). Mother, Father, spouse are family members. Now his wife claims according to Christian Succession Act father and widow are considered as legal heirs (50% to widow). She argue that family member certificate is different from legal heir certificate. The company proposed 1/3 rd benefit to each member. EPF, EDLI, Gratuity, Group Term Life Insurance, Final Settlement are benefits to be given from company. Now the questions are 1. For insurance, how can she claim 50% as she is not nominee or beneficial nominee. Is it true that Full share can be claimed by nominees only in insurance cases? 2. Who will be final beneficiary in EPF, Gratuity, EDLl? (Because I studied these will be applicable to nominees while FD, Mutual Funds, Shares to legal heirs.) 3. How the property divided? 4. Finally, what share will my parents get? and she get? Thank you