My sister was having a beer so I want one too.
Did nobody give you one?
I had to wait longer for mine than she did.
It is fine to want some alcohol, as long as you are of age. You just have to wait your turn at times.
I'm turning 21 in two years, so I want one now.
I can understand it can be hard to wait, but you shouldn't drink if you are underage. There are rules in place for a reason. Don't be in such a hurry to do things so quickly.