Compared to housewifery, psoriasis has a positive image,"" mourns happy homemaker Terry Hekker, who'd take Phyllis McGinley (""my own patron saint"") over Gloria Steinem--or Marabel Morgan. She resents the libbers who demean full-time mothering, but she's all for women's equality, having long ago noticed that boys ""could grow up and become priests and say mass on the altar and we could grow up and become nuns and clean the altar."" And she's all for marriage, but down on divorce--""second-hand merchandise"" is no bargain--so she says caveat emptor and even concedes the merits of living together first. Mrs. Hekker is one of the lucky ones--sheltered enough to think silence is ""the only inhumane weapon"" in domestic warfare, and companionably matched: ""Or have I missed the point again? Is sex after all the bread of life while I've been treating it like the butter. . . ?"" If she generalizes as much as the Friedans and Schlaflys she criticizes--babies are sensual, big families are wonderful, men are unfit for housework (although sharing it is a grand idea)--she draws on her personal history for authority, on how Mama and Grandma practiced ""the world's second oldest profession."" Some of her stories are shaggy-dog staples, not the plain truth, but an article on the housewife as an endangered species has already earned Mrs. Hekker a following--and she sticks up for all the Good Housekeepers stoutly.