*** Moved from US Embassy/Consulate Discussion to the RUB regional forum, to be among other threads about options for beneficiaries of the U4U program ***
What is your visa case category? F2A or F2B? If F2B, what is your case Priority Date (PD)?
If your case is F2A, then you may be able to file I-485 to adjust status in the US now. U4U parolee may file I-485, assuming a visa number is immediately available. You may need to check your I-94 status, though.
If your case is F2B, it depends on your case PD. As for getting a GC through your sister, that is not an option for you in the near future. F4 (sibling of USC) cases take 15+ years, counting from petition filing date.