Deceased father's Pension Fun Claim

My brother passed away on 13 December 2024. Before he passed, he was retrenche by RAF. He was in the process of withdrawing his pension fund from Alexander Forbes. He died before the withdrawal could be processed, and Alexander Forbes reversed the withdrawal. Now, his daughter, wants to know if she is a beneficiary, and how she can go about putting in a claim. Alexander Forbes say they can't give her the information because she is not the executor of the estate. My brother's wife appointed herself as the xecutor, and she refuses to give us any information about the pension fund. Alexander Forbes say the wife is the only one who has access to the information, because she is the executor. We are stu k now because my brother's wife is not talking to us, and we don’t know what to do.