What is the name of this BOOK???!?!?

the main character is a girl (forgot her name) and a kid named jack (i think) who is a bad kid. He moves in witht his family and its huge. The only other things i remember is like the uncle or something directs a play with the sound of music and the girl does like a erfly project and feeds it melon. and one day jake is singing and the uncles sais he should be in the play.... and their chef is like this indian guy who makes spicy food.....yeah thats all i rememeber