@Shizomist Depending on the author's age, "kid" could refer to anyone from the age of 10 to the age of 110. It's not really an age bracket, it's a term of endearment.
Also, while
I would definitely never encourage anyone to break their respective country's drinking laws, whatever they may be, let's not hide behind our pinkies here, underage drinking has always been a thing. As well as, like this chapter shows, people legally drinking whose maturity hasn't
quite caught up to their age.