回複：我姐想要我收養她女兒

Your sister's daugter can apply for student visa to study for two years during which your sister give your gardianship. after two years, after you are a citizen, you can apply green card for her before she is ?? year old( I forgot the age). I just read a book regarding this and it is the same case happened in the book. The book is called "My experience as a lawyer in the U.S.A".

It just you never know what would happens. She might not be as expected as you or your sister expected.