The trouble with most of the new YA novels dealing with sex is that seventeen-year-old behavior, presuming seventeen-year-old feelings, is depicted in stories read chiefly by twelve-year-olds--and, in truth, written at their level. Steptoe's thin but pointed first novel is different. Marcia is only fourteen, and though her boyfriend Danny is pushing her to have sex she herself feels unready; you can see other girls her age empathizing totally and those a little younger relating with understanding. Marcia makes two impassioned, soapbox speeches--one on aggression and manhood to her boyfriend, one on birth control to her mother--which express more confusion than she realizes (and perhaps more than Steptoe realizes), and feminists might well fault the author not only for the girls' preoccupation with boys and clothes, but, more important, for his assumption that eventual capitulation is inevitable. (Would it really be worse to lose Danny?) To us, Marcia's mother is a bit too hasty with the same assumption--but no one can fault her alacrity in fixing her daughter up with contraceptives. And, whatever we adults make of its message, Marcia--with its modified black English, sassy dialogue, and underlying earnestness--is an issue book attuned to its intended audience.