Our family was not very holy,"" writes Martha Girlinghousen who apparently is also Susan Cahill in this feisty, funny account of a flee spirit trapped in New York's parochial schools. Martha, youngest of three sisters, just couldn't abide the sanctimoniousness and the despotism of the ""bad-tempered sows"" who instructed the little angels in catechism, charm class, and Regents drills. Sister Agnes (""the Agony"") laid it down in 8--B: ""there is nothing so disgusting as a tough girl."" Martha was a tough girl backed up by a loving, fiercely loyal family. Her grade-school chum Rosie O'Grady was even tougher--she organized a double date for herself and Martha to Madison Square Garden and the rodeo walking the 11 miles from Flushing. But Rosie became Sister Mary Angelica. And Bold Robert Emmet, Martha's first true love, was swallowed up by the Jesuits. Not Martha, she wouldn't believe that Hunter College was ""a hotbed of Communism"" like the nuns said; she didn't join the panel discussion of ""Why Senator [Joseph] McCarthy is a great American."" Still, such is the seductive power of the holy spirit that right after college Martha put on the Novice's habit of the Franciscan Sisters. Oh, dear. ""My heart pounded with a new certainty: wearing three layers of wool serge in ninety-four degree heat was absurd."" You'll cheer Martha, her ungodly classroom insurrections, her proficiency in cursing, her size 30 AA bra, and her Final Great Escape.