Family terms are stated in the official program material, which has been revised, so they must be read there directly. They should not be assumed to follow the derivative rules used in the visa categories.
Write the answers down with the date
Hypothetical example: the couple have three children aged twenty-three, twenty-six and thirty, two of them married. The current official FAQ permits a spouse and unmarried children under twenty-one to be included in the initial Gold Card application; each included family member is subject to a separate DHS processing fee and individual gift. None of these three children fits that family definition, so each would need an independent basis. Record every age and marital status, confirm admissibility and visa availability for each proposed applicant, and re-check the official program page immediately before any fee or gift is paid because the framework can change.
Hypothetical example: a remote subtitle editor wants to include a spouse, a university-age daughter, and an adult son who still lives at home. The first review should list every person separately with date of birth, relationship, passport, intended activity, and any immigration history. Civil certificates settle family relationships, while the current official terms settle who may be included and what is payable; neither should be inferred from another immigration category. Obtain those answers in writing or from dated official material before any household member leaves work or housing. A common error is assuming that financial dependence controls eligibility for an adult child. It may not. If the official material is silent, preserve that uncertainty and seek individualized advice rather than representing an unconfirmed family member as included.