In season one on The Phone Call, Jack says he met Norma at a department store when he bought a tie. In season five on Triangle, Norma mentions she met Jack at a high school dance.
When Kevin comes home he finds Wayne and his new girlfriend sitting on the couch watching TV, she says they are watching Sonny And Cher. In 1971 the The Sonny & Cher Comedy Hour aired at 10pm on Monday nights and was not in syndication until 1996. It would have been impossible to have see it after school in the afternoon.