Filing a relative petition and proving a qualifying relationship is the first
step to obtaining a green card for your child. Each child needs their own
petition.
Children of U.S. Citizens
With an approved petition, your children can immediately apply for an immigrant visa at the U.S. Consulate where they live, or if they are already in the United States in another legal status, they can apply for Adjustment of Status with U.S. Citizenship & Immigration Services (USCIS).
If you are a U.S. citizen marrying a foreigner that has a child (unmarried and
under 18 at the time of your marriage), the child will usually qualify as your
stepchild and will need a separate petition.
Children of Permanent Residents
Filing a relative petition and proving your qualifying relationship gives your child a place in line among other children waiting to immigrate. When the place in line is reached, your child may be eligible to apply to immigrate.
Your child’s place in line will be based on the date you file your petition, so
there is an advantage to filing as soon as possible.
If
you are a permanent resident and marrying a foreigner that has children, you may
also need to file separate petitions for the children. When your husband
or wife's place in line is reached, his or her unmarried children under 21 can
apply as dependents and don't need separate petitions. However, if the
child marries or turns 21 before they immigrate, they will no longer be eligible
as dependents. You should consider filing separate petitions for each child. A
separate petition keeps the child’s place in line among sons and daughters of
permanent residents waiting to immigrate.