If she has a valid ID then she should be able to by alcohol for herself, you on the other hand are only 16 and can not drink buy or have any reason for having alcohol. Thanx's.
A friend of mine once got carded for Abita Root beer in Hattiesburg.
Your sister should be able to buy alcohol unless she doesn't have a license. But you, however, are too young to be consuming alcohol.
Thanks! Your answer is awaiting moderation.