Do dependent children receiving K-2 visas need to travel to the United States at the same time as the K-1 beneficiary?
No, eligible dependent children can travel to the United States on a K-2 visa within a year of the issuance of the K-1 visa to the principal beneficiary.
This is true even if the K-1 beneficiary has subsequently married, provided the dependent child is still unmarried and under 21 years of age at the time of K-2 issuance.
If a dependent child of your Fiance seeks to enter the United States more than one year after your Fiance has received a K-1 visa, it will be necessary to file an immigrant visa petition for the child.
Should I include all of my Fiance’s children in the K visa petition?
USCIS holds that all children of a K-1 beneficiary must be listed on the visa petition.
If the beneficiary has a child not named in the petition, the consular officer must suspend action and return the petition to USCIS for reconsideration.