How much weight can I lose following this diet?

i am 12 yrs old, turning 13 and i have got a party in 11 days, on the 18th. I am 1.57 m high (5'2') and 43 kg (95 lb) and i want to lose some weight. please dont tell me im young or i dont need to lose weight. no rude comments! so the diet i'm following is: a cup of plain, no sugar added corn flakes for breakfast. nothing in between. then for lunch maybe fish or meat or pulses (im not sure but not something fried or with sauces and stuff). half a peach or half an apple or half a pear or a handful of gs for in between. nothing, or just a gl of orange juice for dinner. so how much weight can i lose if i follow this diet for 11 days and also excersice moderately and doing abs?