World Esquire Law Firm | Aime Katambwe
I don't know how long it is going to take. No one does. But you will have to look at the USDOS Visa Bulletin from time to time to see where she is (will be) in the process. The link there is http://www.travel.state.gov/visa/bulletin/bulletin_5452.html. It is pretty self-explanatory. You are looking at about 10-15 years before she can apply for her immigrant visa assuming it is filed in the next few weeks or so. Good luck!
Answer Applies to: California
Fong & Associates | William D. Fong
Your sister is a 4th preference, so if you file now, the priority date will be current in approximately eleven years according to the DOS visa bulletin. Regardless, you should consider filing for her to get her a place in line. To do that, you need to file the relative petition and then you will wait for the priority date to be current. Please review this information and contact me for more details. We do a lot of work in the South Asian community. Thank you.
Answer Applies to: Texas