i am 19 years old. my yunger sister is 17. right now all she gets for mail is credit card aplications. all i get in the mail is credit card rejection letters. i dont have any credit and neather does she. But i am the only one that is old enough to have a credit card. so how can she be getting pre-approved card aplications and all im getting is rejected?

What reasons are issuers giving for your credit card rejections? What types of cards are you applying for? You might be setting your sites too high. At your age you probably have a limited credit history. If you are a student you should look at student cards. Also, before you jump to conclusions about your sister having all the luck, check out the article "pre-approved credit card offers" in this sites learn section.