Any payments to or on account of any child or children of a deceased or temporarily or totally permanently disabled worker pursuant to any of the provisions of chapter
51.32 RCW shall terminate when any such child reaches the age of eighteen years unless such child is a dependent invalid child or is permanently enrolled at a full time course in an accredited school, in which case such payments after age eighteen shall be made directly to such child. Payments to any dependent invalid child over the age of eighteen years shall continue in the amount previously paid on account of such child until he or she shall cease to be dependent. Payments to any child over the age of eighteen years permanently enrolled at a full time course in an accredited school shall continue in the amount previously paid on account of such child until the child reaches an age over that provided for in the definition of "child" in this title or ceases to be permanently enrolled whichever occurs first. Where the worker sustains an injury or dies when any of the worker's children is over the age of eighteen years and is either a dependent invalid child or is a child permanently enrolled at a full time course in an accredited school the payment to or on account of any such child shall be made as herein provided.