Accompanying and traveling to USA being a guardian of an American minor citizen.?

My sister is an American citizen, she lives with us in Bangladesh and she is a minor(15 years old). Now we want to send her to the United States for a better high school education. My parents are very busy people with their work. Being her elder brother can I go with her to the USA and settle her there and get back to Bangladesh. Will I get a visa anyway? As for me, I am a Bangladeshi citizen, however I have been to USA with my parents before and I have no other intentions like residing in USA illegally or stuffs like that.