""This is how NOT a princess I am. I am so NOT a princess that when my dad started telling me I was one, I totally started crying."" Raised in a Greenwich Village loft in New York City by her flaky-but-loving artist mother, ninth grader Mia Thermopolis is shocked to learn from her father that she is now the heir apparent to Genovia, the tiny European kingdom he rules. Her paternal grandmother further disrupts Mia's life when she comes to town to mold the girl into a proper royal. Cabot's debut children's novel is essentially a classic makeover tale souped up on imperial steroids: a better haircut and an improved wardrobe garner Mia the attention of a hitherto unattainable boy. (Of course this boy isn't all he appears to be, and another boyDthe true friend Mia mostly takes for grantedDturns out to be Mr. Right.) A running gag involving sexual harassment (including a foot fetishist obsessed with Mia's best friend Lilly Moscovitz and a sidewalk groper dubbed the ""Blind Guy"") is more creepy than funny, and the portrayal of the self-conscious pseudo-zaniness of downtown life is over the top (Lilly's parents, both psychoanalysts, get Rolfed, practice t'ai chi and attend benefits for ""the homosexual children of survivors of the Holocaust""). Though Mia's loopy narration has its charms and princess stories can be irresistible, a slapstick cartoonishness prevails here. Ages 12-up. (Oct.) FYI: Plans are in the works for a Disney film to be directed by Garry Marshall and starring Julie Andrews as the grandmother.