I'm 12 and i'm trying to lose about 40 pounds because i'm overweight. Is this under eating?,if not is it a balance diet?

Break-fast
1 slice of toast with with light flora butter.
juice
or
tea with 2 sugars and milk.

lunch
fruit salad
or
ham sandwich
or
cheese sandwich
with
smooth pickle(only with sandwich)
and
some still water

dinner
meat(mainly chicken)with rice and some vegetables.
or soup
or some type of pasta(lasagna,pasta bake,spaghetti,bolonase etc)

on fridays between break-fast and lunch i might have a chicken burger from school.
or
after school on a friday only a chocolate bar.
or
for lunch some oreo biscuits.(2-3)

and maybe every other week,i will have chips,or something like that.

If i stick to this diet and exercise at least 3-5 times a week will i eventually have a body like this girl in a violet minny skirt,and violet shirt on the second to last,part of the page on the right hand side.
http://www.next.co.uk/shopping/children/oldergirls/12