Qualifying assistants can accompany O-1 holders to US on O-2 visa. Spouse and children under 21 can come to the US with O-1 holders on O-3 visa.
This non-immigrant status is available to those who will accompany and assist in the artistic or athletic performance of an O-1 holder. To qualify for O-2 status, the alien must be an “integral part” of the actual performance and have “critical skills and experience” with the O-1 alien which are not of a general nature and which cannot be performed by U.S. workers.
Any spouse or children under the age of 21 who wish to accompany an O-1 or O-2 holders can apply for O-3 visa to enter the US. O-3 visa will have the same duration as the O-1 principal.