How long will take to get my sister into the US?

Right now the waiting time is 9 years. The waiting time changes from time to time.

Assuming you are a U.S. Citizen, which is unclear from the question, then when you reach 21 years of age you can file an I-130 petition for your sister with USCIS. The processing dates vary with demand and work load but currently the petitions are decided after about six months from filing if you live in the Western part of the U.S. Assuming the I-130 is approved, you then can file paperwork to immigrate your sister with the National Visa Center of the Department of State, using the I-130 approval from USCIS as a basis and starting point. This stage of the process is somewhat involved, but assuming you qualify in terms of income to immigrate her, then you apply and wait. Since your sister is not considered an immediate relative, she has to wait for a visa to become current in her visa preference category. Again, processing times vary with demand and workload, but there is a special factor in waiting for a visa to become current. Only a certain number of visas are created each year, and they are distributed according to a system of preferences which can be compared to a fountain with water that drips down many levels to the bottom. A visa for the brother or sister of a U.S. citizen is at the very bottom, below all other categories. There is a rough way of predicting the wait. Right now, visas are becoming current for applicants for the Dominican Republic in your sister's visa preference category where the priority date from USCIS was 01JAN02, almost nine years ago. If the pace of applications filed and visas created continues indefinitely into the future, then you can expect roughly that it will take nine years from the time you file with USCIS and the application is accepted before a visa will become current for your sister, who will likely have to wait outside of the U.S. until it does. Please note that without a retainer agreement, we do not represent you or your sister, no communication is attorney client privileged, and we cannot be responsible for your sister's case.

For an answer, you must look at the Visa bulletin, a monthly publication by the Department of State. It states the date for each category. The January 2011 visa bulletin indicates 1-1-2002 for 4th preference (USC sibling filing for another), Dominican Republic. This means that a person whose American sibling who filed a family petition before 2002 can now apply for an immigrant visa. In this case, this means about 9 years.