Under the current rules, a main applicant of the St. Kitts and Nevis citizenship by investment program can include his/her immediate family on an application:
Spouse;
Minor children, including children from previous marriages of the main applicant or his/her spouse;
Children up to 30 years of age provided that they are unmarried and financially dependent on their parents;
Parents/grandparents of both spouses over 55 years old provided they are fully financially dependent on the main applicant;
Siblings under the age of 30 who are unmarried and financially dependent on the main applicant.
Remember that including dependents on your application will increase your investment (if you make a non-refundable donation to the Sustainable Growth Fund) and your additional payments to the state. For example, it will cost you $4,000 for a due diligence check for each additional adult.