All agencies for relief, such as widows’ pensions as provided by law, aid under the authority of the rehabilitation commission and public employment service, or other aids to relief, support or assistance, public or private, shall be made use of by overseers and their subordinates and helpers to the end that causes of dependency on the part of persons or their families and the need for such public relief in whole or in part may be eliminated, and such subordinates and helpers are authorized under direction of the overseer or deputy to take such legal steps, either as prosecutors or petitioners in legal proceedings in aid of such persons or their families as may be necessary to such end.