If I'm a USA citizen and want to petition for my 7 year old sister to come live with me since are father past away how long would it take

Generally speaking, there is no expedite for the F-4 petition request for sibling that you are contemplating. This type of petition takes approximately 12 years to complete. You can try to have her come over under a humanitarian parole, but the instructions say that the use of humanitarian parole is not to speed up immigrant processing. I imagine that you would have to supply much evidence of the desperate nature of the circumstance before the case would even be considered. Forms and instructions can be accessed on the U.S.C.I.S. website under form I-131. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.