An excellent article in the Military e-Times explains:
“You probably know that a child can receive Social Security benefits on a parent’s record if the parent is receiving disability or retirement benefits or as the survivor of a parent who is deceased. But did you know that while most Social Security benefits for children end when a child reaches age 18, a child — if blind or disabled — may qualify for benefits as a “disabled adult child” well past that age?
Disabled adult children may include biological and adopted children, and sometimes even a stepchild, grandchild or step-grandchild. To qualify for disabled adult child benefits, the child must be unmarried, at least 18 years old and must have a disability that began before reaching age 22. As long as the adult child was disabled before age 22, continues to be disabled and did not work, the child may be eligible. See full story here: