How can i gain weight fast?

ok im am very tiny skinney im am about to turn 14 im verry small like i have no , , belly, etc. skinneyness runs in my family. i hate being called a stick a twig and stuff like that i just want to have a bigger body frame so i can fit into more clothes. i always have to were a belt aand i haate it! im skinny and tall about 5'2 1/2 and im sick of being like 90 pounds! help!