We like to think that the author of To Tell Your Love (P 424-1950) will soon set the standard for teen-age fiction for girls. This novel about nursing has the same freshness of touch, depth of characterization and charm in heroines. The three girls who pace the action of this novel -- which could double as a career story for prospective nurses -- are refreshingly intelligent, ambitious and womanly at the same time, but hardly superwomen. There is lovely Gretchen, direct, enthusiastic about her work, emotionally uncomplicated until she finds herself in love; competent, but shy Nelle, overshadowed by a flirtatious and feather brained mother, who forces her to a superficial freeze; lonely Rosemary, bitterly hating the woman who took her dead mother's place as step-mother. To be sure, the girls pair off with suitable men, but their affection and dedication to their work is enriched -- not diverted, by masculine attention. A realistic inside view of the hospital, too, with basins as well as starched uniforms. Clever chatter.