How old do you have to be to go to an mcr concert ?

i am going to one in a couple of days , its with me and two of my friends . i bought four tickets and my 11 year old sister is like juping of the walls and screeming and begging to come with me . im ok with it , is just my parents are concerned . they almost didnt want me to go ! let alone my little sister . so they said untill i find out , then she cant come . and if she doesnt come ... you wont be hearing much of me on yahoo answers any more ! So it would really be a help if you could tell me . i am trying to convince my parents that i think there is no age limmit . heck my sister probably knows as many bad words as i do , so it really doesnt matter . Cuz for fans , you know how gerard always goes," ok guys, i want you all to put you motherfu*king hands together ",and all that . thats why they think she isnt allowed to go cuz of her age . If there isnt an age limmit ( which i dont think there is ) , then i will happily show this page to my mother and father and MAKE them let her go !