She's a Naturalized US citizen, am her niece.
She's a Naturalized US citizen, am her niece.
For you immigrate through an immediate relative who is a U.S. citizen, the relative must be a spouse, your parent if you are under 21 and unmarried, or your adult (> 21 year old) child.
If you want to try to get a student visa, that would allow you to remain in the U.S. during your studies - but not to become a permanent resident.