No person who is otherwise eligible for support under this chapter shall receive such support unless and until all able-bodied adults under the age of 65 years, except those regularly attending school, who are related to such person, regularly residing in the same household as such person, legally liable to contribute to the support of such person and not prevented from maintaining employment and contributing to the support of such person by reason of physical or mental disability or other substantial or other justifiable cause, are employed on a full-time basis. The amount or amounts earned by the persons obligated to maintain employment under this section shall be taken into consideration in determining the level of need for support. Nothing in this section shall be so construed to deny to any minor dependent child any needed support to which he would otherwise be entitled. Unrelated adults living in the same household in loco parentis as to any such person seeking county support shall be obligated to contribute to the poor person’s support to the same extent as the parent of such person, and in default thereof, shall be subject to the same penalties as the parent of such person would be in such case.