You are a 13 year old girl who wants to be in a Twilight movie but there are no other parts other then Leah and Seth Clearwater which you need special critiria for which you don't have What do you do?

Well you could always be in other movies. Also Twilight might need extras for their upcoming movies so keep your ears open. If Twilight doesn't work out for you, then keep taking acting classes and pursue your dreams, and you could end up starring in someting bigger than Twilight!