text: If you are a US Citizen you may petition for the following foreign national relatives to immigrate to the United States; however you must be able to provide proof of the relationships:\n\n* Husband or wife;\n* Unmarried child under 21 years old;\n* Unmarried son or daughter over 21;\n* Married son or daughter of any age;\n* Brother or sister, if you are at least 21 years old; or\n* Parent, if you are at least 21 years old.