Bad sibling removed all money from deceased mother's account after 40 days?

My mother just passed away. There are no surviving parents but five surviving children. Mother did not have a lot to speak of. She did have a small bank account under a balance of $3,000. She did not leave a beneficiary in this account. It was understood that I would handle the bank affairs no one at the time including me know what to do. When I went to my mom’s bank after 40 days I found out that one of my siblings had underhandedly removed the funds and closed the account behind our back. Is this legal? Do all the siblings just wait at a branch of the deceased first thing in the morning, on the 41st day and the fastest bank executive to process the paper work and scan the death certificate awards the winner? It just does not sound right? Did my sister who took the money have to sign anything to swear there were not other interested siblings? Do I have recourse?