This article is from the FAQ, by with numerous contributions by others.
I was looking over all your K-1 Visa information and noticed
that there is nothing mentioned in detail regarding the parent
bringing children with to the U.S. - When filling out fiance'
papers, children are, of course, normally included with on the
application when one is filled out. However, since MY Fiance'
will be bringing her child with FROM the Ukraine, she is also
required to obtain from her ex-husband, his permission, in
certified writing, to allow her to bring the child. Also,
these "permission" papers must also be translated into English
and certified. My Fiance' submits these "permission" papers
with her own documents to the U.S. Consulate in Warsaw,
Poland. This does not mean of course, that the father gives
up his rights for the child, but merely allows the child to
move to the U.S. - Separate legal action, after the child has
arrived into the U.S. can then be taken-up to attempt adoption
by the new "step-parent". I do not know, at this time, if
there are similar requirements for "permission papers" from
other countries. I wanted to pass this information on to you
and any interested readers. If anyone would like additional
information regarding the information I just offered, they are
welcome to contact me via e-mail and I will gladly try to