The Foreign Affairs Manual states the dependent of a principal in the US in a Non-immigrant visa (NIV) status may obtain the NI Visa as long as the principal maintains the status in the U.S.
9 FAM 402.1-6 ISSUANCE OF NONIMMIGRANT VISAS (NIV) TO SPOUSES AND/OR CHILDREN WHEN PRINCIPAL IS IN STATUS BUT HAS NO VISA.
Derivative beneficiaries are entitled to apply for visas to follow and/or join a principal applicant who is maintaining legal status in the United States, even when the principal applicant was never issued a valid visa in the classification being sought for by the spouse and dependent children.
