My mother and I opened a joint account several years ago so she would have access to money when she came to stay for long visits. Can we close and distribute the account?

She has had Alzheimer's for about 4 years now and has been in an assisted living home for almost years.  The account was set up so that either her or I  could withdraw money. 
 She is 95 and my brother has been her POA, which all of us siblings agreed on. There's still $9000 in that account. Can we close the account and go ahead and distribute it between the 8 children? Her care is covered and she has prepaid her funeral expenses.