On-court excitement and off-court bathos mix in Walden's latest. Cindy Banner is on a relentless route from dirt-poor but picturesque Lighthouse Cove to center court at Wimbledon, and nothing will stop her. Not a soggy romance with wealthy, junior champ Steve Scott (who has a rep), not the media meanies who criticize her psych-out style, and certainly not a succession of opponents who always seem overpowering at first but never go the distance. But will Cindy find life as a pro as empty as that of her glamorous, sometimes-coach Jennie Roland? Will she be able to leave her horridly named--Elf, Cricket, Jimsy--and cloyingly supportive friends? Better lay in a supply of sweatbands and handkerchiefs.