boys size 12 is for a 26 inch waist, and a boys size 14 is for a 28" this is no size 13, but there are "slims" and "Husky" versions of size 12's and 14's. Boys at this age can be problematic to fit because of the obvious differences in ages and physical maturity of boys between the ages of 10 -14, hip size and everything else can be radically different from one boy to another who are technically the same "size." Tip: NEVER buy a boy pants without him being able to try them on first. They grow from week to week.
That is about a size 3/4 or 5/6. Of course the size of your legs and rear could mean that you run a size up or down.
It also depends on your hip size, but generally that's somewhere between a size 6 and a size 8 (based on US sizes).
Approximately US size 8.
I wear a size 3-5 and my waist size is usually a 27-29 inch. it also depends on the style of the pants though - if they are high waisted you may be able to wear something smaller than if they are low-rise.
THAT'S ABOUT A 26-27 INCH WAIST.
No, it is rather slim, really.
There is no set waist size for a size 2. Or any women's sizes for that matter. The number is arbitrary and differs from brand to brand. A women's size 2 can vary from a 25 inch waist to a 35 inch waist going from brand to brand, there has never been any regulation within the fashion industry that says "a size two has to have these dimensions" and so forth, although it has been suggested many times. Even designer brands which label their jeans in waist sizes, like 26 or 27, do not match up their "sizes" with the actual measurements of their jeans. I have a pair of size 26 Seven jeans which are not actually 26 inches around the waist.