You are allowed to file an I-130 petition for your sister. Unless she is eligible under 245i, then she can't file for the actual green card in the US. She would need to consular process, which would trigger a ten year bar to entry. You really need to have a full consult with a competent immigration attorney to determine if the U visa, or any other visa can apply to her and also to determine if an I-130 filing is a good idea for her.
Answered on Sep 29th, 2011 at 1:44 PM