Unpaid claim for divorce decree

I lodge funeral claim for my divorced sisters daughter ,on the 2 january 2025 at east London office.They said payments takes only 48 hours to pay.Today i received call from them telling me that they need decree if divorce of my sister's daughter. I told that in the Death certificate the Status of marriage is written ,and i don't know where can i get it because the deceased in question did not married with me also did not give me decree of divorce before she die . I only want to bury her body .