One EB-5 investment will qualify the main investor, the investor’s spouse, and their unmarried children under the age of 21 to immigration together to the United States. And as long as you make the investment and file the I-526 immigration petition before your child turns 21, your child will qualify to immigration with you. (Once the I-526 is approved, you must file for Adjustment of Status or apply for consular processing within one-year of the approval.)
However, this only holds true for non-Chinese investors. As of May 1, 2015, EB-5 visas for people born in China has backlogged. So if you were born in China please read our article on the Chinese visa backlog (a/k/a retrogression – although this is technically not correct) and the age-out issue of children born in China.